diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index f8e2c0e11..49621f55f 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -55,7 +55,7 @@ module ApplicationHelper
 
   def fa_icon(icon, attributes = {})
     class_names = attributes[:class]&.split(' ') || []
-    class_names << 'fa'
+    class_names << 'fas'
     class_names += icon.split(' ').map { |cl| "fa-#{cl}" }
 
     content_tag(:i, nil, attributes.merge(class: class_names.join(' ')))
diff --git a/app/javascript/mastodon/components/__tests__/__snapshots__/avatar-test.js.snap b/app/javascript/mastodon/components/__tests__/__snapshots__/avatar-test.js.snap
index f6f6bfbf4..1ab59836a 100644
--- a/app/javascript/mastodon/components/__tests__/__snapshots__/avatar-test.js.snap
+++ b/app/javascript/mastodon/components/__tests__/__snapshots__/avatar-test.js.snap
@@ -15,7 +15,7 @@ exports[`<Avatar /> Autoplay renders a animated avatar 1`] = `
   }
 >
   <i
-    className="fa fa-fw fa-robot bot-icon"
+    className="fas fa-fw fa-robot bot-icon"
   />
 </div>
 `;
@@ -35,7 +35,7 @@ exports[`<Avatar /> Still renders a still avatar 1`] = `
   }
 >
   <i
-    className="fa fa-fw fa-robot bot-icon"
+    className="fas fa-fw fa-robot bot-icon"
   />
 </div>
 `;
diff --git a/app/javascript/mastodon/components/attachment_list.js b/app/javascript/mastodon/components/attachment_list.js
index 8e5bb0e0b..14e6cfc65 100644
--- a/app/javascript/mastodon/components/attachment_list.js
+++ b/app/javascript/mastodon/components/attachment_list.js
@@ -24,7 +24,7 @@ export default class AttachmentList extends ImmutablePureComponent {
 
               return (
                 <li key={attachment.get('id')}>
-                  <a href={displayUrl} target='_blank' rel='noopener'><i className='fa fa-link' /> {filename(displayUrl)}</a>
+                  <a href={displayUrl} target='_blank' rel='noopener'><i className='fas fa-link' /> {filename(displayUrl)}</a>
                 </li>
               );
             })}
@@ -36,7 +36,7 @@ export default class AttachmentList extends ImmutablePureComponent {
     return (
       <div className='attachment-list'>
         <div className='attachment-list__icon'>
-          <i className='fa fa-link' />
+          <i className='fas fa-link' />
         </div>
 
         <ul className='attachment-list__list'>
diff --git a/app/javascript/mastodon/components/bot_icon.js b/app/javascript/mastodon/components/bot_icon.js
index f4bd70282..4d824e762 100644
--- a/app/javascript/mastodon/components/bot_icon.js
+++ b/app/javascript/mastodon/components/bot_icon.js
@@ -13,7 +13,7 @@ export default class BotIcon extends ImmutablePureComponent {
 
     if (account.get('bot')) {
       return (
-        <i className='fa fa-fw fa-robot bot-icon' />
+        <i className='fas fa-fw fa-robot bot-icon' />
       );
     }
 
diff --git a/app/javascript/mastodon/components/column_back_button.js b/app/javascript/mastodon/components/column_back_button.js
index 8a60c4192..2560e31ee 100644
--- a/app/javascript/mastodon/components/column_back_button.js
+++ b/app/javascript/mastodon/components/column_back_button.js
@@ -19,7 +19,7 @@ export default class ColumnBackButton extends React.PureComponent {
   render () {
     return (
       <button onClick={this.handleClick} className='column-back-button'>
-        <i className='fa fa-fw fa-chevron-left column-back-button__icon' />
+        <i className='fas fa-fw fa-chevron-left column-back-button__icon' />
         <FormattedMessage id='column_back_button.label' defaultMessage='Back' />
       </button>
     );
diff --git a/app/javascript/mastodon/components/column_back_button_slim.js b/app/javascript/mastodon/components/column_back_button_slim.js
index 964c100be..a0d111aa7 100644
--- a/app/javascript/mastodon/components/column_back_button_slim.js
+++ b/app/javascript/mastodon/components/column_back_button_slim.js
@@ -8,7 +8,7 @@ export default class ColumnBackButtonSlim extends ColumnBackButton {
     return (
       <div className='column-back-button--slim'>
         <div role='button' tabIndex='0' onClick={this.handleClick} className='column-back-button column-back-button--slim-button'>
-          <i className='fa fa-fw fa-chevron-left column-back-button__icon' />
+          <i className='fas fa-fw fa-chevron-left column-back-button__icon' />
           <FormattedMessage id='column_back_button.label' defaultMessage='Back' />
         </div>
       </div>
diff --git a/app/javascript/mastodon/components/column_header.js b/app/javascript/mastodon/components/column_header.js
index 613df1e79..420ce3eef 100644
--- a/app/javascript/mastodon/components/column_header.js
+++ b/app/javascript/mastodon/components/column_header.js
@@ -95,22 +95,22 @@ class ColumnHeader extends React.PureComponent {
     }
 
     if (multiColumn && pinned) {
-      pinButton = <button key='pin-button' className='text-btn column-header__setting-btn' onClick={onPin}><i className='fa fa fa-times' /> <FormattedMessage id='column_header.unpin' defaultMessage='Unpin' /></button>;
+      pinButton = <button key='pin-button' className='text-btn column-header__setting-btn' onClick={onPin}><i className='fas fa-times' /> <FormattedMessage id='column_header.unpin' defaultMessage='Unpin' /></button>;
 
       moveButtons = (
         <div key='move-buttons' className='column-header__setting-arrows'>
-          <button title={formatMessage(messages.moveLeft)} aria-label={formatMessage(messages.moveLeft)} className='text-btn column-header__setting-btn' onClick={this.handleMoveLeft}><i className='fa fa-chevron-left' /></button>
-          <button title={formatMessage(messages.moveRight)} aria-label={formatMessage(messages.moveRight)} className='text-btn column-header__setting-btn' onClick={this.handleMoveRight}><i className='fa fa-chevron-right' /></button>
+          <button title={formatMessage(messages.moveLeft)} aria-label={formatMessage(messages.moveLeft)} className='text-btn column-header__setting-btn' onClick={this.handleMoveLeft}><i className='fas fa-chevron-left' /></button>
+          <button title={formatMessage(messages.moveRight)} aria-label={formatMessage(messages.moveRight)} className='text-btn column-header__setting-btn' onClick={this.handleMoveRight}><i className='fas fa-chevron-right' /></button>
         </div>
       );
     } else if (multiColumn) {
-      pinButton = <button key='pin-button' className='text-btn column-header__setting-btn' onClick={onPin}><i className='fa fa fa-plus' /> <FormattedMessage id='column_header.pin' defaultMessage='Pin' /></button>;
+      pinButton = <button key='pin-button' className='text-btn column-header__setting-btn' onClick={onPin}><i className='fas fa-plus' /> <FormattedMessage id='column_header.pin' defaultMessage='Pin' /></button>;
     }
 
     if (!pinned && (multiColumn || showBackButton)) {
       backButton = (
         <button onClick={this.handleBackClick} className='column-header__back-button'>
-          <i className='fa fa-fw fa-chevron-left column-back-button__icon' />
+          <i className='fas fa-fw fa-chevron-left column-back-button__icon' />
           <FormattedMessage id='column_back_button.label' defaultMessage='Back' />
         </button>
       );
@@ -126,7 +126,7 @@ class ColumnHeader extends React.PureComponent {
     }
 
     if (children || multiColumn) {
-      collapseButton = <button className={collapsibleButtonClassName} title={formatMessage(collapsed ? messages.show : messages.hide)} aria-label={formatMessage(collapsed ? messages.show : messages.hide)} aria-pressed={collapsed ? 'false' : 'true'} onClick={this.handleToggleClick}><i className='fa fa-sliders-h' /></button>;
+      collapseButton = <button className={collapsibleButtonClassName} title={formatMessage(collapsed ? messages.show : messages.hide)} aria-label={formatMessage(collapsed ? messages.show : messages.hide)} aria-pressed={collapsed ? 'false' : 'true'} onClick={this.handleToggleClick}><i className='fas fa-sliders-h' /></button>;
     }
 
     const hasTitle = icon && title;
@@ -136,7 +136,7 @@ class ColumnHeader extends React.PureComponent {
         <h1 className={buttonClassName}>
           {hasTitle && (
             <button onClick={this.handleTitleClick}>
-              <i className={`fa fa-fw fa-${icon} column-header__icon`} />
+              <i className={`fas fa-fw fa-${icon} column-header__icon`} />
               {title}
             </button>
           )}
diff --git a/app/javascript/mastodon/components/icon_button.js b/app/javascript/mastodon/components/icon_button.js
index b96e48fd0..a303064ff 100644
--- a/app/javascript/mastodon/components/icon_button.js
+++ b/app/javascript/mastodon/components/icon_button.js
@@ -86,7 +86,7 @@ export default class IconButton extends React.PureComponent {
           style={style}
           tabIndex={tabIndex}
         >
-          <i className={`fa fa-fw fa-${icon}`} aria-hidden='true' />
+          <i className={`fas fa-fw fa-${icon}`} aria-hidden='true' />
         </button>
       );
     }
@@ -104,7 +104,7 @@ export default class IconButton extends React.PureComponent {
             style={style}
             tabIndex={tabIndex}
           >
-            <i style={{ transform: `rotate(${rotate}deg)` }} className={`fa fa-fw fa-${icon}`} aria-hidden='true' />
+            <i style={{ transform: `rotate(${rotate}deg)` }} className={`fas fa-fw fa-${icon}`} aria-hidden='true' />
           </button>
         )}
       </Motion>
diff --git a/app/javascript/mastodon/components/load_gap.js b/app/javascript/mastodon/components/load_gap.js
index ed4d445d0..7c7e8fe1e 100644
--- a/app/javascript/mastodon/components/load_gap.js
+++ b/app/javascript/mastodon/components/load_gap.js
@@ -25,7 +25,7 @@ class LoadGap extends React.PureComponent {
 
     return (
       <button className='load-more load-gap' disabled={disabled} onClick={this.handleClick} aria-label={intl.formatMessage(messages.load_more)}>
-        <i className='fa fa-ellipsis-h' />
+        <i className='fas fa-ellipsis-h' />
       </button>
     );
   }
diff --git a/app/javascript/mastodon/components/status.js b/app/javascript/mastodon/components/status.js
index 90c689a75..08fecce5a 100644
--- a/app/javascript/mastodon/components/status.js
+++ b/app/javascript/mastodon/components/status.js
@@ -193,7 +193,7 @@ class Status extends ImmutablePureComponent {
     if (featured) {
       prepend = (
         <div className='status__prepend'>
-          <div className='status__prepend-icon-wrapper'><i className='fa fa-fw fa-thumb-tack status__prepend-icon' /></div>
+          <div className='status__prepend-icon-wrapper'><i className='fas fa-fw fa-thumbtack status__prepend-icon' /></div>
           <FormattedMessage id='status.pinned' defaultMessage='Pinned toot' />
         </div>
       );
@@ -202,7 +202,7 @@ class Status extends ImmutablePureComponent {
 
       prepend = (
         <div className='status__prepend'>
-          <div className='status__prepend-icon-wrapper'><i className='fa fa-fw fa-retweet status__prepend-icon' /></div>
+          <div className='status__prepend-icon-wrapper'><i className='fas fa-fw fa-retweet status__prepend-icon' /></div>
           <FormattedMessage id='status.reblogged_by' defaultMessage='{name} boosted' values={{ name: <a onClick={this.handleAccountClick} data-id={status.getIn(['account', 'id'])} href={status.getIn(['account', 'url'])} className='status__display-name muted'><bdi><strong dangerouslySetInnerHTML={display_name_html} /></bdi></a> }} />
         </div>
       );
diff --git a/app/javascript/mastodon/features/account/components/header.js b/app/javascript/mastodon/features/account/components/header.js
index a762b4902..4934e7a27 100644
--- a/app/javascript/mastodon/features/account/components/header.js
+++ b/app/javascript/mastodon/features/account/components/header.js
@@ -150,7 +150,7 @@ class Header extends ImmutablePureComponent {
     }
 
     if (account.get('locked')) {
-      lockedIcon = <i className='fa fa-lock' />;
+      lockedIcon = <i className='fas fa-lock' />;
     }
 
     const content         = { __html: account.get('note_emojified') };
@@ -177,7 +177,7 @@ class Header extends ImmutablePureComponent {
                   <dt dangerouslySetInnerHTML={{ __html: pair.get('name_emojified') }} title={pair.get('name')} />
 
                   <dd className={pair.get('verified_at') && 'verified'} title={pair.get('value_plain')}>
-                    {pair.get('verified_at') && <span title={intl.formatMessage(messages.linkVerifiedOn, { date: intl.formatDate(pair.get('verified_at'), dateFormatOptions) })}><i className='fa fa-check verified__mark' /></span>} <span dangerouslySetInnerHTML={{ __html: pair.get('value_emojified') }} />
+                    {pair.get('verified_at') && <span title={intl.formatMessage(messages.linkVerifiedOn, { date: intl.formatDate(pair.get('verified_at'), dateFormatOptions) })}><i className='fas fa-check verified__mark' /></span>} <span dangerouslySetInnerHTML={{ __html: pair.get('value_emojified') }} />
                   </dd>
                 </dl>
               ))}
diff --git a/app/javascript/mastodon/features/account_timeline/components/moved_note.js b/app/javascript/mastodon/features/account_timeline/components/moved_note.js
index 280389bba..ff3290031 100644
--- a/app/javascript/mastodon/features/account_timeline/components/moved_note.js
+++ b/app/javascript/mastodon/features/account_timeline/components/moved_note.js
@@ -33,7 +33,7 @@ export default class MovedNote extends ImmutablePureComponent {
     return (
       <div className='account__moved-note'>
         <div className='account__moved-note__message'>
-          <div className='account__moved-note__icon-wrapper'><i className='fa fa-fw fa-suitcase account__moved-note__icon' /></div>
+          <div className='account__moved-note__icon-wrapper'><i className='fas fa-fw fa-suitcase account__moved-note__icon' /></div>
           <FormattedMessage id='account.moved_to' defaultMessage='{name} has moved to:' values={{ name: <bdi><strong dangerouslySetInnerHTML={displayNameHtml} /></bdi> }} />
         </div>
 
diff --git a/app/javascript/mastodon/features/compose/components/compose_form.js b/app/javascript/mastodon/features/compose/components/compose_form.js
index 365114b93..199d11fcb 100644
--- a/app/javascript/mastodon/features/compose/components/compose_form.js
+++ b/app/javascript/mastodon/features/compose/components/compose_form.js
@@ -160,7 +160,7 @@ class ComposeForm extends ImmutablePureComponent {
     let publishText = '';
 
     if (this.props.privacy === 'private' || this.props.privacy === 'direct') {
-      publishText = <span className='compose-form__publish-private'><i className='fa fa-lock' /> {intl.formatMessage(messages.publish)}</span>;
+      publishText = <span className='compose-form__publish-private'><i className='fas fa-lock' /> {intl.formatMessage(messages.publish)}</span>;
     } else {
       publishText = this.props.privacy !== 'unlisted' ? intl.formatMessage(messages.publishLoud, { publish: intl.formatMessage(messages.publish) }) : intl.formatMessage(messages.publish);
     }
diff --git a/app/javascript/mastodon/features/compose/components/privacy_dropdown.js b/app/javascript/mastodon/features/compose/components/privacy_dropdown.js
index 7b5482f05..43d0c73a4 100644
--- a/app/javascript/mastodon/features/compose/components/privacy_dropdown.js
+++ b/app/javascript/mastodon/features/compose/components/privacy_dropdown.js
@@ -132,7 +132,7 @@ class PrivacyDropdownMenu extends React.PureComponent {
             {items.map(item => (
               <div role='option' tabIndex='0' key={item.value} data-index={item.value} onKeyDown={this.handleKeyDown} onClick={this.handleClick} className={classNames('privacy-dropdown__option', { active: item.value === value })} aria-selected={item.value === value} ref={item.value === value ? this.setFocusRef : null}>
                 <div className='privacy-dropdown__option__icon'>
-                  <i className={`fa fa-fw fa-${item.icon}`} />
+                  <i className={`fas fa-fw fa-${item.icon}`} />
                 </div>
 
                 <div className='privacy-dropdown__option__content'>
diff --git a/app/javascript/mastodon/features/compose/components/search.js b/app/javascript/mastodon/features/compose/components/search.js
index d203d8780..8245dadd6 100644
--- a/app/javascript/mastodon/features/compose/components/search.js
+++ b/app/javascript/mastodon/features/compose/components/search.js
@@ -116,8 +116,8 @@ class Search extends React.PureComponent {
         </label>
 
         <div role='button' tabIndex='0' className='search__icon' onClick={this.handleClear}>
-          <i className={`fa fa-search ${hasValue ? '' : 'active'}`} />
-          <i aria-label={intl.formatMessage(messages.placeholder)} className={`fa fa-times-circle ${hasValue ? 'active' : ''}`} />
+          <i className={`fas fa-search ${hasValue ? '' : 'active'}`} />
+          <i aria-label={intl.formatMessage(messages.placeholder)} className={`fas fa-times-circle ${hasValue ? 'active' : ''}`} />
         </div>
 
         <Overlay show={expanded && !hasValue} placement='bottom' target={this}>
diff --git a/app/javascript/mastodon/features/compose/components/search_results.js b/app/javascript/mastodon/features/compose/components/search_results.js
index c351b84bb..51496c00b 100644
--- a/app/javascript/mastodon/features/compose/components/search_results.js
+++ b/app/javascript/mastodon/features/compose/components/search_results.js
@@ -22,7 +22,7 @@ export default class SearchResults extends ImmutablePureComponent {
       count   += results.get('accounts').size;
       accounts = (
         <div className='search-results__section'>
-          <h5><i className='fa fa-fw fa-users' /><FormattedMessage id='search_results.accounts' defaultMessage='People' /></h5>
+          <h5><i className='fas fa-fw fa-users' /><FormattedMessage id='search_results.accounts' defaultMessage='People' /></h5>
 
           {results.get('accounts').map(accountId => <AccountContainer key={accountId} id={accountId} />)}
         </div>
@@ -33,7 +33,7 @@ export default class SearchResults extends ImmutablePureComponent {
       count   += results.get('statuses').size;
       statuses = (
         <div className='search-results__section'>
-          <h5><i className='fa fa-fw fa-quote-right' /><FormattedMessage id='search_results.statuses' defaultMessage='Toots' /></h5>
+          <h5><i className='fas fa-fw fa-quote-right' /><FormattedMessage id='search_results.statuses' defaultMessage='Toots' /></h5>
 
           {results.get('statuses').map(statusId => <StatusContainer key={statusId} id={statusId} />)}
         </div>
@@ -44,7 +44,7 @@ export default class SearchResults extends ImmutablePureComponent {
       count += results.get('hashtags').size;
       hashtags = (
         <div className='search-results__section'>
-          <h5><i className='fa fa-fw fa-hashtag' /><FormattedMessage id='search_results.hashtags' defaultMessage='Hashtags' /></h5>
+          <h5><i className='fas fa-fw fa-hashtag' /><FormattedMessage id='search_results.hashtags' defaultMessage='Hashtags' /></h5>
 
           {results.get('hashtags').map(hashtag => <Hashtag key={hashtag.get('name')} hashtag={hashtag} />)}
         </div>
@@ -54,7 +54,7 @@ export default class SearchResults extends ImmutablePureComponent {
     return (
       <div className='search-results'>
         <div className='search-results__header'>
-          <i className='fa fa-search fa-fw' />
+          <i className='fas fa-search fa-fw' />
           <FormattedMessage id='search_results.total' defaultMessage='{count, number} {count, plural, one {result} other {results}}' values={{ count }} />
         </div>
 
diff --git a/app/javascript/mastodon/features/compose/components/upload.js b/app/javascript/mastodon/features/compose/components/upload.js
index e377da90c..fd3f9f94f 100644
--- a/app/javascript/mastodon/features/compose/components/upload.js
+++ b/app/javascript/mastodon/features/compose/components/upload.js
@@ -89,8 +89,8 @@ class Upload extends ImmutablePureComponent {
           {({ scale }) => (
             <div className='compose-form__upload-thumbnail' style={{ transform: `scale(${scale})`, backgroundImage: `url(${media.get('preview_url')})`, backgroundPosition: `${x}% ${y}%` }}>
               <div className={classNames('compose-form__upload__actions', { active })}>
-                <button className='icon-button' onClick={this.handleUndoClick}><i className='fa fa-times' /> <FormattedMessage id='upload_form.undo' defaultMessage='Delete' /></button>
-                {media.get('type') === 'image' && <button className='icon-button' onClick={this.handleFocalPointClick}><i className='fa fa-crosshairs' /> <FormattedMessage id='upload_form.focus' defaultMessage='Crop' /></button>}
+                <button className='icon-button' onClick={this.handleUndoClick}><i className='fas fa-times' /> <FormattedMessage id='upload_form.undo' defaultMessage='Delete' /></button>
+                {media.get('type') === 'image' && <button className='icon-button' onClick={this.handleFocalPointClick}><i className='fas fa-crosshairs' /> <FormattedMessage id='upload_form.focus' defaultMessage='Crop' /></button>}
               </div>
 
               <div className={classNames('compose-form__upload-description', { active })}>
diff --git a/app/javascript/mastodon/features/compose/components/upload_progress.js b/app/javascript/mastodon/features/compose/components/upload_progress.js
index d5e6f19cd..949989b26 100644
--- a/app/javascript/mastodon/features/compose/components/upload_progress.js
+++ b/app/javascript/mastodon/features/compose/components/upload_progress.js
@@ -21,7 +21,7 @@ export default class UploadProgress extends React.PureComponent {
     return (
       <div className='upload-progress'>
         <div className='upload-progress__icon'>
-          <i className='fa fa-upload' />
+          <i className='fas fa-upload' />
         </div>
 
         <div className='upload-progress__message'>
diff --git a/app/javascript/mastodon/features/compose/index.js b/app/javascript/mastodon/features/compose/index.js
index 6f1b9b71d..398e1fc97 100644
--- a/app/javascript/mastodon/features/compose/index.js
+++ b/app/javascript/mastodon/features/compose/index.js
@@ -76,21 +76,21 @@ class Compose extends React.PureComponent {
       const { columns } = this.props;
       header = (
         <nav className='drawer__header'>
-          <Link to='/getting-started' className='drawer__tab' title={intl.formatMessage(messages.start)} aria-label={intl.formatMessage(messages.start)}><i role='img' className='fa fa-fw fa-bars' /></Link>
+          <Link to='/getting-started' className='drawer__tab' title={intl.formatMessage(messages.start)} aria-label={intl.formatMessage(messages.start)}><i role='img' className='fas fa-fw fa-bars' /></Link>
           {!columns.some(column => column.get('id') === 'HOME') && (
-            <Link to='/timelines/home' className='drawer__tab' title={intl.formatMessage(messages.home_timeline)} aria-label={intl.formatMessage(messages.home_timeline)}><i role='img' className='fa fa-fw fa-home' /></Link>
+            <Link to='/timelines/home' className='drawer__tab' title={intl.formatMessage(messages.home_timeline)} aria-label={intl.formatMessage(messages.home_timeline)}><i role='img' className='fas fa-fw fa-home' /></Link>
           )}
           {!columns.some(column => column.get('id') === 'NOTIFICATIONS') && (
-            <Link to='/notifications' className='drawer__tab' title={intl.formatMessage(messages.notifications)} aria-label={intl.formatMessage(messages.notifications)}><i role='img' className='fa fa-fw fa-bell' /></Link>
+            <Link to='/notifications' className='drawer__tab' title={intl.formatMessage(messages.notifications)} aria-label={intl.formatMessage(messages.notifications)}><i role='img' className='fas fa-fw fa-bell' /></Link>
           )}
           {!columns.some(column => column.get('id') === 'COMMUNITY') && (
-            <Link to='/timelines/public/local' className='drawer__tab' title={intl.formatMessage(messages.community)} aria-label={intl.formatMessage(messages.community)}><i role='img' className='fa fa-fw fa-users' /></Link>
+            <Link to='/timelines/public/local' className='drawer__tab' title={intl.formatMessage(messages.community)} aria-label={intl.formatMessage(messages.community)}><i role='img' className='fas fa-fw fa-users' /></Link>
           )}
           {!columns.some(column => column.get('id') === 'PUBLIC') && (
-            <Link to='/timelines/public' className='drawer__tab' title={intl.formatMessage(messages.public)} aria-label={intl.formatMessage(messages.public)}><i role='img' className='fa fa-fw fa-globe' /></Link>
+            <Link to='/timelines/public' className='drawer__tab' title={intl.formatMessage(messages.public)} aria-label={intl.formatMessage(messages.public)}><i role='img' className='fas fa-fw fa-globe' /></Link>
           )}
-          <a href='/settings/preferences' className='drawer__tab' title={intl.formatMessage(messages.preferences)} aria-label={intl.formatMessage(messages.preferences)}><i role='img' className='fa fa-fw fa-cog' /></a>
-          <a href='/auth/sign_out' className='drawer__tab' data-method='delete' title={intl.formatMessage(messages.logout)} aria-label={intl.formatMessage(messages.logout)}><i role='img' className='fa fa-fw fa-sign-out-alt' /></a>
+          <a href='/settings/preferences' className='drawer__tab' title={intl.formatMessage(messages.preferences)} aria-label={intl.formatMessage(messages.preferences)}><i role='img' className='fas fa-fw fa-cog' /></a>
+          <a href='/auth/sign_out' className='drawer__tab' data-method='delete' title={intl.formatMessage(messages.logout)} aria-label={intl.formatMessage(messages.logout)}><i role='img' className='fas fa-fw fa-sign-out-alt' /></a>
         </nav>
       );
     }
diff --git a/app/javascript/mastodon/features/getting_started/index.js b/app/javascript/mastodon/features/getting_started/index.js
index d5ba5cbce..4fbe7ed5a 100644
--- a/app/javascript/mastodon/features/getting_started/index.js
+++ b/app/javascript/mastodon/features/getting_started/index.js
@@ -120,7 +120,7 @@ class GettingStarted extends ImmutablePureComponent {
         {multiColumn && <div className='column-header__wrapper'>
           <h1 className='column-header'>
             <button>
-              <i className='fa fa-bars fa-fw column-header__icon' />
+              <i className='fas fa-bars fa-fw column-header__icon' />
               <FormattedMessage id='getting_started.heading' defaultMessage='Getting started' />
             </button>
           </h1>
diff --git a/app/javascript/mastodon/features/list_editor/components/search.js b/app/javascript/mastodon/features/list_editor/components/search.js
index f7617fe58..24f2c7d5d 100644
--- a/app/javascript/mastodon/features/list_editor/components/search.js
+++ b/app/javascript/mastodon/features/list_editor/components/search.js
@@ -65,8 +65,8 @@ class Search extends React.PureComponent {
         </label>
 
         <div role='button' tabIndex='0' className='search__icon' onClick={this.handleClear}>
-          <i className={classNames('fa fa-search', { active: !hasValue })} />
-          <i aria-label={intl.formatMessage(messages.search)} className={classNames('fa fa-times-circle', { active: hasValue })} />
+          <i className={classNames('fas fa-search', { active: !hasValue })} />
+          <i aria-label={intl.formatMessage(messages.search)} className={classNames('fas fa-times-circle', { active: hasValue })} />
         </div>
       </div>
     );
diff --git a/app/javascript/mastodon/features/list_timeline/index.js b/app/javascript/mastodon/features/list_timeline/index.js
index 55f675cd3..78ea7624a 100644
--- a/app/javascript/mastodon/features/list_timeline/index.js
+++ b/app/javascript/mastodon/features/list_timeline/index.js
@@ -150,11 +150,11 @@ class ListTimeline extends React.PureComponent {
         >
           <div className='column-header__links'>
             <button className='text-btn column-header__setting-btn' tabIndex='0' onClick={this.handleEditClick}>
-              <i className='fa fa-pencil-alt' /> <FormattedMessage id='lists.edit' defaultMessage='Edit list' />
+              <i className='fas fa-pencil-alt' /> <FormattedMessage id='lists.edit' defaultMessage='Edit list' />
             </button>
 
             <button className='text-btn column-header__setting-btn' tabIndex='0' onClick={this.handleDeleteClick}>
-              <i className='fa fa-trash' /> <FormattedMessage id='lists.delete' defaultMessage='Delete list' />
+              <i className='fas fa-trash' /> <FormattedMessage id='lists.delete' defaultMessage='Delete list' />
             </button>
           </div>
 
diff --git a/app/javascript/mastodon/features/notifications/components/clear_column_button.js b/app/javascript/mastodon/features/notifications/components/clear_column_button.js
index e0bf4c82d..ea1249e86 100644
--- a/app/javascript/mastodon/features/notifications/components/clear_column_button.js
+++ b/app/javascript/mastodon/features/notifications/components/clear_column_button.js
@@ -10,7 +10,7 @@ export default class ClearColumnButton extends React.PureComponent {
 
   render () {
     return (
-      <button className='text-btn column-header__setting-btn' tabIndex='0' onClick={this.props.onClick}><i className='fa fa-eraser' /> <FormattedMessage id='notifications.clear' defaultMessage='Clear notifications' /></button>
+      <button className='text-btn column-header__setting-btn' tabIndex='0' onClick={this.props.onClick}><i className='fas fa-eraser' /> <FormattedMessage id='notifications.clear' defaultMessage='Clear notifications' /></button>
     );
   }
 
diff --git a/app/javascript/mastodon/features/notifications/components/notification.js b/app/javascript/mastodon/features/notifications/components/notification.js
index ed4a44ca6..c256661af 100644
--- a/app/javascript/mastodon/features/notifications/components/notification.js
+++ b/app/javascript/mastodon/features/notifications/components/notification.js
@@ -83,7 +83,7 @@ class Notification extends ImmutablePureComponent {
         <div className='notification notification-follow focusable' tabIndex='0' aria-label={notificationForScreenReader(intl, intl.formatMessage({ id: 'notification.follow', defaultMessage: '{name} followed you' }, { name: account.get('acct') }), notification.get('created_at'))}>
           <div className='notification__message'>
             <div className='notification__favourite-icon-wrapper'>
-              <i className='fa fa-fw fa-user-plus' />
+              <i className='fas fa-fw fa-user-plus' />
             </div>
 
             <FormattedMessage id='notification.follow' defaultMessage='{name} followed you' values={{ name: link }} />
@@ -116,7 +116,7 @@ class Notification extends ImmutablePureComponent {
         <div className='notification notification-favourite focusable' tabIndex='0' aria-label={notificationForScreenReader(intl, intl.formatMessage({ id: 'notification.favourite', defaultMessage: '{name} favourited your status' }, { name: notification.getIn(['account', 'acct']) }), notification.get('created_at'))}>
           <div className='notification__message'>
             <div className='notification__favourite-icon-wrapper'>
-              <i className='fa fa-fw fa-star star-icon' />
+              <i className='fas fa-fw fa-star star-icon' />
             </div>
             <FormattedMessage id='notification.favourite' defaultMessage='{name} favourited your status' values={{ name: link }} />
           </div>
@@ -135,7 +135,7 @@ class Notification extends ImmutablePureComponent {
         <div className='notification notification-reblog focusable' tabIndex='0' aria-label={notificationForScreenReader(intl, intl.formatMessage({ id: 'notification.reblog', defaultMessage: '{name} boosted your status' }, { name: notification.getIn(['account', 'acct']) }), notification.get('created_at'))}>
           <div className='notification__message'>
             <div className='notification__favourite-icon-wrapper'>
-              <i className='fa fa-fw fa-retweet' />
+              <i className='fas fa-fw fa-retweet' />
             </div>
             <FormattedMessage id='notification.reblog' defaultMessage='{name} boosted your status' values={{ name: link }} />
           </div>
diff --git a/app/javascript/mastodon/features/pinned_statuses/index.js b/app/javascript/mastodon/features/pinned_statuses/index.js
index 98cdbda3c..298d0f8c5 100644
--- a/app/javascript/mastodon/features/pinned_statuses/index.js
+++ b/app/javascript/mastodon/features/pinned_statuses/index.js
@@ -46,7 +46,7 @@ class PinnedStatuses extends ImmutablePureComponent {
     const { intl, shouldUpdateScroll, statusIds, hasMore } = this.props;
 
     return (
-      <Column icon='thumb-tack' heading={intl.formatMessage(messages.heading)} ref={this.setRef}>
+      <Column icon='thumbtack' heading={intl.formatMessage(messages.heading)} ref={this.setRef}>
         <ColumnBackButtonSlim />
         <StatusList
           statusIds={statusIds}
diff --git a/app/javascript/mastodon/features/status/components/card.js b/app/javascript/mastodon/features/status/components/card.js
index b52f3c4fa..65259cb84 100644
--- a/app/javascript/mastodon/features/status/components/card.js
+++ b/app/javascript/mastodon/features/status/components/card.js
@@ -173,8 +173,8 @@ export default class Card extends React.PureComponent {
 
             <div className='status-card__actions'>
               <div>
-                <button onClick={this.handleEmbedClick}><i className={`fa fa-${iconVariant}`} /></button>
-                <a href={card.get('url')} target='_blank' rel='noopener'><i className='fa fa-external-link' /></a>
+                <button onClick={this.handleEmbedClick}><i className={`fas fa-${iconVariant}`} /></button>
+                <a href={card.get('url')} target='_blank' rel='noopener'><i className='fas fa-external-link-alt' /></a>
               </div>
             </div>
           </div>
diff --git a/app/javascript/mastodon/features/status/components/detailed_status.js b/app/javascript/mastodon/features/status/components/detailed_status.js
index b4bbda161..7f5d50743 100644
--- a/app/javascript/mastodon/features/status/components/detailed_status.js
+++ b/app/javascript/mastodon/features/status/components/detailed_status.js
@@ -94,10 +94,10 @@ export default class DetailedStatus extends ImmutablePureComponent {
     }
 
     if (status.get('visibility') === 'private') {
-      reblogLink = <i className={`fa fa-${reblogIcon}`} />;
+      reblogLink = <i className={`fas fa-${reblogIcon}`} />;
     } else {
       reblogLink = (<Link to={`/statuses/${status.get('id')}/reblogs`} className='detailed-status__link'>
-        <i className={`fa fa-${reblogIcon}`} />
+        <i className={`fas fa-${reblogIcon}`} />
         <span className='detailed-status__reblogs'>
           <FormattedNumber value={status.get('reblogs_count')} />
         </span>
@@ -119,7 +119,7 @@ export default class DetailedStatus extends ImmutablePureComponent {
           <a className='detailed-status__datetime' href={status.get('url')} target='_blank' rel='noopener'>
             <FormattedDate value={new Date(status.get('created_at'))} hour12={false} year='numeric' month='short' day='2-digit' hour='2-digit' minute='2-digit' />
           </a>{applicationLink} · {reblogLink} · <Link to={`/statuses/${status.get('id')}/favourites`} className='detailed-status__link'>
-            <i className='fa fa-star' />
+            <i className='fas fa-star' />
             <span className='detailed-status__favorites'>
               <FormattedNumber value={status.get('favourites_count')} />
             </span>
diff --git a/app/javascript/mastodon/features/status/index.js b/app/javascript/mastodon/features/status/index.js
index 7d1bc2ca4..a9fe4c885 100644
--- a/app/javascript/mastodon/features/status/index.js
+++ b/app/javascript/mastodon/features/status/index.js
@@ -410,7 +410,7 @@ class Status extends ImmutablePureComponent {
         <ColumnHeader
           showBackButton
           extraButton={(
-            <button className='column-header__button' title={intl.formatMessage(status.get('hidden') ? messages.revealAll : messages.hideAll)} aria-label={intl.formatMessage(status.get('hidden') ? messages.revealAll : messages.hideAll)} onClick={this.handleToggleAll} aria-pressed={status.get('hidden') ? 'false' : 'true'}><i className={`fa fa-${status.get('hidden') ? 'eye-slash' : 'eye'}`} /></button>
+            <button className='column-header__button' title={intl.formatMessage(status.get('hidden') ? messages.revealAll : messages.hideAll)} aria-label={intl.formatMessage(status.get('hidden') ? messages.revealAll : messages.hideAll)} onClick={this.handleToggleAll} aria-pressed={status.get('hidden') ? 'false' : 'true'}><i className={`fas fa-${status.get('hidden') ? 'eye-slash' : 'eye'}`} /></button>
           )}
         />
 
diff --git a/app/javascript/mastodon/features/ui/components/boost_modal.js b/app/javascript/mastodon/features/ui/components/boost_modal.js
index b128e67d2..f20ea4c36 100644
--- a/app/javascript/mastodon/features/ui/components/boost_modal.js
+++ b/app/javascript/mastodon/features/ui/components/boost_modal.js
@@ -74,7 +74,7 @@ class BoostModal extends ImmutablePureComponent {
         </div>
 
         <div className='boost-modal__action-bar'>
-          <div><FormattedMessage id='boost_modal.combo' defaultMessage='You can press {combo} to skip this next time' values={{ combo: <span>Shift + <i className='fa fa-retweet' /></span> }} /></div>
+          <div><FormattedMessage id='boost_modal.combo' defaultMessage='You can press {combo} to skip this next time' values={{ combo: <span>Shift + <i className='fas fa-retweet' /></span> }} /></div>
           <Button text={intl.formatMessage(messages.reblog)} onClick={this.handleReblog} ref={this.setRef} />
         </div>
       </div>
diff --git a/app/javascript/mastodon/features/ui/components/column_header.js b/app/javascript/mastodon/features/ui/components/column_header.js
index e8bdd8054..db544b7d6 100644
--- a/app/javascript/mastodon/features/ui/components/column_header.js
+++ b/app/javascript/mastodon/features/ui/components/column_header.js
@@ -21,7 +21,7 @@ export default class ColumnHeader extends React.PureComponent {
     let iconElement = '';
 
     if (icon) {
-      iconElement = <i className={`fa fa-fw fa-${icon} column-header__icon`} />;
+      iconElement = <i className={`fas fa-fw fa-${icon} column-header__icon`} />;
     }
 
     return (
diff --git a/app/javascript/mastodon/features/ui/components/column_link.js b/app/javascript/mastodon/features/ui/components/column_link.js
index 25c2d1cf8..f6bb4f6f6 100644
--- a/app/javascript/mastodon/features/ui/components/column_link.js
+++ b/app/javascript/mastodon/features/ui/components/column_link.js
@@ -8,7 +8,7 @@ const ColumnLink = ({ icon, text, to, href, method, badge }) => {
   if (href) {
     return (
       <a href={href} className='column-link' data-method={method}>
-        <i className={`fa fa-fw fa-${icon} column-link__icon`} />
+        <i className={`fas fa-fw fa-${icon} column-link__icon`} />
         {text}
         {badgeElement}
       </a>
@@ -16,7 +16,7 @@ const ColumnLink = ({ icon, text, to, href, method, badge }) => {
   } else {
     return (
       <Link to={to} className='column-link'>
-        <i className={`fa fa-fw fa-${icon} column-link__icon`} />
+        <i className={`fas fa-fw fa-${icon} column-link__icon`} />
         {text}
         {badgeElement}
       </Link>
diff --git a/app/javascript/mastodon/features/ui/components/columns_area.js b/app/javascript/mastodon/features/ui/components/columns_area.js
index 4cce2f6e0..f3ba3ba13 100644
--- a/app/javascript/mastodon/features/ui/components/columns_area.js
+++ b/app/javascript/mastodon/features/ui/components/columns_area.js
@@ -160,7 +160,7 @@ class ColumnsArea extends ImmutablePureComponent {
     this.pendingIndex = null;
 
     if (singleColumn) {
-      const floatingActionButton = shouldHideFAB(this.context.router.history.location.pathname) ? null : <Link key='floating-action-button' to='/statuses/new' className='floating-action-button' aria-label={intl.formatMessage(messages.publish)}><i className='fa fa-pencil-alt' /></Link>;
+      const floatingActionButton = shouldHideFAB(this.context.router.history.location.pathname) ? null : <Link key='floating-action-button' to='/statuses/new' className='floating-action-button' aria-label={intl.formatMessage(messages.publish)}><i className='fas fa-pencil-alt' /></Link>;
 
       return columnIndex !== -1 ? [
         <ReactSwipeableViews key='content' index={columnIndex} onChangeIndex={this.handleSwipe} onTransitionEnd={this.handleAnimationEnd} animateTransitions={shouldAnimate} springConfig={{ duration: '400ms', delay: '0s', easeFunction: 'ease' }} style={{ height: '100%' }}>
diff --git a/app/javascript/mastodon/features/ui/components/media_modal.js b/app/javascript/mastodon/features/ui/components/media_modal.js
index d29a4a6a7..9aa336e37 100644
--- a/app/javascript/mastodon/features/ui/components/media_modal.js
+++ b/app/javascript/mastodon/features/ui/components/media_modal.js
@@ -108,8 +108,8 @@ class MediaModal extends ImmutablePureComponent {
     const index = this.getIndex();
     let pagination = [];
 
-    const leftNav  = media.size > 1 && <button tabIndex='0' className='media-modal__nav media-modal__nav--left' onClick={this.handlePrevClick} aria-label={intl.formatMessage(messages.previous)}><i className='fa fa-fw fa-chevron-left' /></button>;
-    const rightNav = media.size > 1 && <button tabIndex='0' className='media-modal__nav  media-modal__nav--right' onClick={this.handleNextClick} aria-label={intl.formatMessage(messages.next)}><i className='fa fa-fw fa-chevron-right' /></button>;
+    const leftNav  = media.size > 1 && <button tabIndex='0' className='media-modal__nav media-modal__nav--left' onClick={this.handlePrevClick} aria-label={intl.formatMessage(messages.previous)}><i className='fas fa-fw fa-chevron-left' /></button>;
+    const rightNav = media.size > 1 && <button tabIndex='0' className='media-modal__nav  media-modal__nav--right' onClick={this.handleNextClick} aria-label={intl.formatMessage(messages.next)}><i className='fas fa-fw fa-chevron-right' /></button>;
 
     if (media.size > 1) {
       pagination = media.map((item, i) => {
diff --git a/app/javascript/mastodon/features/ui/components/onboarding_modal.js b/app/javascript/mastodon/features/ui/components/onboarding_modal.js
index 25241bcd0..3688d9412 100644
--- a/app/javascript/mastodon/features/ui/components/onboarding_modal.js
+++ b/app/javascript/mastodon/features/ui/components/onboarding_modal.js
@@ -262,11 +262,11 @@ class OnboardingModal extends React.PureComponent {
 
     const nextOrDoneBtn = hasMore ? (
       <button onClick={this.handleNext} className='onboarding-modal__nav onboarding-modal__next shake-bottom'>
-        <FormattedMessage id='onboarding.next' defaultMessage='Next' /> <i className='fa fa-fw fa-chevron-right' />
+        <FormattedMessage id='onboarding.next' defaultMessage='Next' /> <i className='fas fa-fw fa-chevron-right' />
       </button>
     ) : (
       <button onClick={this.handleClose} className='onboarding-modal__nav onboarding-modal__done shake-bottom'>
-        <FormattedMessage id='onboarding.done' defaultMessage='Done' /> <i className='fa fa-fw fa-check' />
+        <FormattedMessage id='onboarding.done' defaultMessage='Done' /> <i className='fas fa-fw fa-check' />
       </button>
     );
 
diff --git a/app/javascript/mastodon/features/ui/components/tabs_bar.js b/app/javascript/mastodon/features/ui/components/tabs_bar.js
index 16236ea51..3f2e5478a 100644
--- a/app/javascript/mastodon/features/ui/components/tabs_bar.js
+++ b/app/javascript/mastodon/features/ui/components/tabs_bar.js
@@ -6,14 +6,14 @@ import { debounce } from 'lodash';
 import { isUserTouching } from '../../../is_mobile';
 
 export const links = [
-  <NavLink className='tabs-bar__link primary' to='/timelines/home' data-preview-title-id='column.home' data-preview-icon='home' ><i className='fa fa-fw fa-home' /><FormattedMessage id='tabs_bar.home' defaultMessage='Home' /></NavLink>,
-  <NavLink className='tabs-bar__link primary' to='/notifications' data-preview-title-id='column.notifications' data-preview-icon='bell' ><i className='fa fa-fw fa-bell' /><FormattedMessage id='tabs_bar.notifications' defaultMessage='Notifications' /></NavLink>,
+  <NavLink className='tabs-bar__link primary' to='/timelines/home' data-preview-title-id='column.home' data-preview-icon='home' ><i className='fas fa-fw fa-home' /><FormattedMessage id='tabs_bar.home' defaultMessage='Home' /></NavLink>,
+  <NavLink className='tabs-bar__link primary' to='/notifications' data-preview-title-id='column.notifications' data-preview-icon='bell' ><i className='fas fa-fw fa-bell' /><FormattedMessage id='tabs_bar.notifications' defaultMessage='Notifications' /></NavLink>,
 
-  <NavLink className='tabs-bar__link secondary' to='/timelines/public/local' data-preview-title-id='column.community' data-preview-icon='users' ><i className='fa fa-fw fa-users' /><FormattedMessage id='tabs_bar.local_timeline' defaultMessage='Local' /></NavLink>,
-  <NavLink className='tabs-bar__link secondary' exact to='/timelines/public' data-preview-title-id='column.public' data-preview-icon='globe' ><i className='fa fa-fw fa-globe' /><FormattedMessage id='tabs_bar.federated_timeline' defaultMessage='Federated' /></NavLink>,
-  <NavLink className='tabs-bar__link primary' to='/search' data-preview-title-id='tabs_bar.search' data-preview-icon='bell' ><i className='fa fa-fw fa-search' /><FormattedMessage id='tabs_bar.search' defaultMessage='Search' /></NavLink>,
+  <NavLink className='tabs-bar__link secondary' to='/timelines/public/local' data-preview-title-id='column.community' data-preview-icon='users' ><i className='fas fa-fw fa-users' /><FormattedMessage id='tabs_bar.local_timeline' defaultMessage='Local' /></NavLink>,
+  <NavLink className='tabs-bar__link secondary' exact to='/timelines/public' data-preview-title-id='column.public' data-preview-icon='globe' ><i className='fas fa-fw fa-globe' /><FormattedMessage id='tabs_bar.federated_timeline' defaultMessage='Federated' /></NavLink>,
+  <NavLink className='tabs-bar__link primary' to='/search' data-preview-title-id='tabs_bar.search' data-preview-icon='bell' ><i className='fas fa-fw fa-search' /><FormattedMessage id='tabs_bar.search' defaultMessage='Search' /></NavLink>,
 
-  <NavLink className='tabs-bar__link primary' style={{ flexGrow: '0', flexBasis: '30px' }} to='/getting-started' data-preview-title-id='getting_started.heading' data-preview-icon='bars' ><i className='fa fa-fw fa-bars' /></NavLink>,
+  <NavLink className='tabs-bar__link primary' style={{ flexGrow: '0', flexBasis: '30px' }} to='/getting-started' data-preview-title-id='getting_started.heading' data-preview-icon='bars' ><i className='fas fa-fw fa-bars' /></NavLink>,
 ];
 
 export function getIndex (path) {
diff --git a/app/javascript/mastodon/features/video/index.js b/app/javascript/mastodon/features/video/index.js
index 67f7580b9..9ef098605 100644
--- a/app/javascript/mastodon/features/video/index.js
+++ b/app/javascript/mastodon/features/video/index.js
@@ -353,10 +353,10 @@ class Video extends React.PureComponent {
 
           <div className='video-player__buttons-bar'>
             <div className='video-player__buttons left'>
-              <button type='button' aria-label={intl.formatMessage(paused ? messages.play : messages.pause)} onClick={this.togglePlay}><i className={classNames('fa fa-fw', { 'fa-play': paused, 'fa-pause': !paused })} /></button>
-              <button type='button' aria-label={intl.formatMessage(muted ? messages.unmute : messages.mute)} onClick={this.toggleMute}><i className={classNames('fa fa-fw', { 'fa-volume-off': muted, 'fa-volume-up': !muted })} /></button>
+              <button type='button' aria-label={intl.formatMessage(paused ? messages.play : messages.pause)} onClick={this.togglePlay}><i className={classNames('fas fa-fw', { 'fa-play': paused, 'fa-pause': !paused })} /></button>
+              <button type='button' aria-label={intl.formatMessage(muted ? messages.unmute : messages.mute)} onClick={this.toggleMute}><i className={classNames('fas fa-fw', { 'fa-volume-off': muted, 'fa-volume-up': !muted })} /></button>
 
-              {!onCloseVideo && <button type='button' aria-label={intl.formatMessage(messages.hide)} onClick={this.toggleReveal}><i className='fa fa-fw fa-eye' /></button>}
+              {!onCloseVideo && <button type='button' aria-label={intl.formatMessage(messages.hide)} onClick={this.toggleReveal}><i className='fas fa-fw fa-eye' /></button>}
 
               {(detailed || fullscreen) &&
                 <span>
@@ -368,9 +368,9 @@ class Video extends React.PureComponent {
             </div>
 
             <div className='video-player__buttons right'>
-              {(!fullscreen && onOpenVideo) && <button type='button' aria-label={intl.formatMessage(messages.expand)} onClick={this.handleOpenVideo}><i className='fa fa-fw fa-expand' /></button>}
-              {onCloseVideo && <button type='button' aria-label={intl.formatMessage(messages.close)} onClick={this.handleCloseVideo}><i className='fa fa-fw fa-compress' /></button>}
-              <button type='button' aria-label={intl.formatMessage(fullscreen ? messages.exit_fullscreen : messages.fullscreen)} onClick={this.toggleFullscreen}><i className={classNames('fa fa-fw', { 'fa-arrows-alt': !fullscreen, 'fa-compress': fullscreen })} /></button>
+              {(!fullscreen && onOpenVideo) && <button type='button' aria-label={intl.formatMessage(messages.expand)} onClick={this.handleOpenVideo}><i className='fas fa-fw fa-expand' /></button>}
+              {onCloseVideo && <button type='button' aria-label={intl.formatMessage(messages.close)} onClick={this.handleCloseVideo}><i className='fas fa-fw fa-compress' /></button>}
+              <button type='button' aria-label={intl.formatMessage(fullscreen ? messages.exit_fullscreen : messages.fullscreen)} onClick={this.toggleFullscreen}><i className={classNames('fas fa-fw', { 'fa-arrows-alt': !fullscreen, 'fa-compress': fullscreen })} /></button>
             </div>
           </div>
         </div>
diff --git a/app/javascript/styles/mastodon/about.scss b/app/javascript/styles/mastodon/about.scss
index dc456be3e..06a5f83d1 100644
--- a/app/javascript/styles/mastodon/about.scss
+++ b/app/javascript/styles/mastodon/about.scss
@@ -1113,7 +1113,7 @@ $small-breakpoint: 960px;
         align-items: center;
         margin-left: 15px;
 
-        .fa {
+        .fas {
           display: block;
           color: $darker-text-color;
           font-size: 48px;
diff --git a/app/javascript/styles/mastodon/accounts.scss b/app/javascript/styles/mastodon/accounts.scss
index 06effbdb2..830c64d50 100644
--- a/app/javascript/styles/mastodon/accounts.scss
+++ b/app/javascript/styles/mastodon/accounts.scss
@@ -136,7 +136,7 @@
     float: left;
     padding-left: 0;
 
-    .fa {
+    .fas {
       display: inline-block;
       margin-right: 5px;
     }
@@ -146,7 +146,7 @@
     float: right;
     padding-right: 0;
 
-    .fa {
+    .fas {
       display: inline-block;
       margin-left: 5px;
     }
diff --git a/app/javascript/styles/mastodon/admin.scss b/app/javascript/styles/mastodon/admin.scss
index b6c771abf..1ae4aa1fe 100644
--- a/app/javascript/styles/mastodon/admin.scss
+++ b/app/javascript/styles/mastodon/admin.scss
@@ -50,7 +50,7 @@ $no-columns-breakpoint: 600px;
         transition: all 200ms linear;
         border-radius: 4px 0 0 4px;
 
-        i.fa {
+        i.fas {
           margin-right: 5px;
         }
 
diff --git a/app/javascript/styles/mastodon/components.scss b/app/javascript/styles/mastodon/components.scss
index c57f99fea..dd440d16f 100644
--- a/app/javascript/styles/mastodon/components.scss
+++ b/app/javascript/styles/mastodon/components.scss
@@ -675,7 +675,7 @@
     &:hover {
       text-decoration: underline;
 
-      .fa {
+      .fas {
         color: lighten($dark-text-color, 7%);
       }
     }
@@ -690,7 +690,7 @@
       }
     }
 
-    .fa {
+    .fas {
       color: $dark-text-color;
     }
   }
@@ -1496,7 +1496,7 @@ a.account__display-name {
   font-size: 15px;
   position: relative;
 
-  .fa {
+  .fas {
     color: $highlight-text-color;
   }
 
@@ -2044,7 +2044,7 @@ a.account__display-name {
   border-bottom: 2px solid lighten($ui-base-color, 8%);
   transition: all 50ms linear;
 
-  .fa {
+  .fas {
     font-weight: 400;
     font-size: 16px;
   }
@@ -3274,7 +3274,7 @@ a.status-card {
   overflow: hidden;
   display: flex;
 
-  .fa {
+  .fas {
     font-size: 34px;
     margin-right: 10px;
   }
@@ -3491,7 +3491,7 @@ a.status-card {
     outline: 0 !important;
   }
 
-  .fa {
+  .fas {
     position: absolute;
     top: 10px;
     right: 10px;
@@ -3545,7 +3545,7 @@ a.status-card {
   font-size: 16px;
   cursor: default;
 
-  .fa {
+  .fas {
     display: inline-block;
     margin-right: 5px;
   }
@@ -3564,7 +3564,7 @@ a.status-card {
     font-size: 16px;
     color: $dark-text-color;
 
-    .fa {
+    .fas {
       display: inline-block;
       margin-right: 5px;
     }
@@ -4462,7 +4462,7 @@ a.status-card {
     justify-content: center;
     font-size: 26px;
 
-    .fa {
+    .fas {
       display: block;
     }
   }
@@ -4500,7 +4500,7 @@ a.status-card {
       display: block;
     }
 
-    .fa {
+    .fas {
       color: $dark-text-color;
     }
   }
@@ -5447,7 +5447,7 @@ noscript {
     font-size: 16px;
     cursor: default;
 
-    .fa {
+    .fas {
       display: inline-block;
       margin-right: 5px;
     }
diff --git a/app/javascript/styles/mastodon/forms.scss b/app/javascript/styles/mastodon/forms.scss
index be2bf7cea..c829023ee 100644
--- a/app/javascript/styles/mastodon/forms.scss
+++ b/app/javascript/styles/mastodon/forms.scss
@@ -656,7 +656,7 @@ code {
         }
       }
 
-      .fa {
+      .fas {
         font-weight: 400;
       }
     }
diff --git a/app/javascript/styles/mastodon/rtl.scss b/app/javascript/styles/mastodon/rtl.scss
index 11588d47f..16d09fa41 100644
--- a/app/javascript/styles/mastodon/rtl.scss
+++ b/app/javascript/styles/mastodon/rtl.scss
@@ -38,7 +38,7 @@ body.rtl {
     padding-left: 30px;
   }
 
-  .search__icon .fa {
+  .search__icon .fas {
     right: auto;
     left: 10px;
   }
@@ -197,7 +197,7 @@ body.rtl {
   }
 
   .admin-wrapper .sidebar ul a i.fa,
-  a.table-action-link i.fa {
+  a.table-action-link i.fas {
     margin-right: 0;
     margin-left: 5px;
   }
@@ -264,7 +264,7 @@ body.rtl {
     left: 0;
   }
 
-  .landing-page .fa-external-link {
+  .landing-page .fa-external-link-alt {
     padding-right: 5px;
     padding-left: 0 !important;
   }
diff --git a/app/javascript/styles/mastodon/tables.scss b/app/javascript/styles/mastodon/tables.scss
index adb75afe5..73195ac0a 100644
--- a/app/javascript/styles/mastodon/tables.scss
+++ b/app/javascript/styles/mastodon/tables.scss
@@ -112,7 +112,7 @@ a.table-action-link {
     color: $primary-text-color;
   }
 
-  i.fa {
+  i.fas {
     font-weight: 400;
     margin-right: 5px;
   }
diff --git a/app/javascript/styles/mastodon/widgets.scss b/app/javascript/styles/mastodon/widgets.scss
index f843f0b42..8267c3f4b 100644
--- a/app/javascript/styles/mastodon/widgets.scss
+++ b/app/javascript/styles/mastodon/widgets.scss
@@ -196,7 +196,7 @@
   &__message {
     margin-bottom: 15px;
 
-    .fa {
+    .fas {
       margin-right: 5px;
       color: $darker-text-color;
     }
diff --git a/app/views/about/_links.html.haml b/app/views/about/_links.html.haml
index f79c37e65..b392b1789 100644
--- a/app/views/about/_links.html.haml
+++ b/app/views/about/_links.html.haml
@@ -13,4 +13,4 @@
     %li
       = link_to 'https://joinmastodon.org/' do
         = "#{t('about.other_instances')}"
-        %i.fa.fa-external-link{ style: 'padding-left: 5px;' }
+        %i.fa.fa-external-link-alt{ style: 'padding-left: 5px;' }
diff --git a/app/views/stream_entries/_status.html.haml b/app/views/stream_entries/_status.html.haml
index 83887cd87..e5b7e695d 100644
--- a/app/views/stream_entries/_status.html.haml
+++ b/app/views/stream_entries/_status.html.haml
@@ -35,7 +35,7 @@
   - elsif pinned
     .status__prepend
       .status__prepend-icon-wrapper
-        %i.status__prepend-icon.fa.fa-fw.fa-thumb-tack
+        %i.status__prepend-icon.fa.fa-fw.fa-thumbtack
       %span
         = t('stream_entries.pinned')
 
diff --git a/spec/helpers/application_helper_spec.rb b/spec/helpers/application_helper_spec.rb
index 61780b46b..af231fe16 100644
--- a/spec/helpers/application_helper_spec.rb
+++ b/spec/helpers/application_helper_spec.rb
@@ -55,7 +55,7 @@ describe ApplicationHelper do
 
   describe 'fa_icon' do
     it 'returns a tag of fixed-width cog' do
-      expect(helper.fa_icon('cog fw')).to eq '<i class="fa fa-cog fa-fw"></i>'
+      expect(helper.fa_icon('cog fw')).to eq '<i class="fas fa-cog fa-fw"></i>'
     end
   end