diff --git a/app/assets/javascripts/blob/viewer/index.js b/app/assets/javascripts/blob/viewer/index.js
new file mode 100644
index 00000000000..47c20d60446
--- /dev/null
+++ b/app/assets/javascripts/blob/viewer/index.js
@@ -0,0 +1,130 @@
+``/* eslint-disable no-new */
+/* global Flash */
+export default class BlobViewer {
+  constructor() {
+    this.switcherBtns = document.querySelectorAll('.js-blob-viewer-switcher');
+    this.copySourceBtn = document.querySelector('.js-copy-blob-source-btn');
+    this.simpleViewer = document.querySelector('.blob-viewer[data-type="simple"]');
+    this.richViewer = document.querySelector('.blob-viewer[data-type="rich"]');
+    this.$blobContentHolder = $('#blob-content-holder');
+
+    let initialViewerName = document.querySelector('.blob-viewer:not(.hidden)').getAttribute('data-type');
+
+    if (this.switcherBtns.length) {
+      this.initBindings();
+
+      if (location.hash.indexOf('#L') === 0) {
+        initialViewerName = 'simple';
+      }
+    }
+
+    this.switchToViewer(initialViewerName);
+  }
+
+  initBindings() {
+    Array.from(this.switcherBtns)
+      .forEach((el) => {
+        el.addEventListener('click', this.switchViewHandler.bind(this));
+      });
+
+    if (this.copySourceBtn) {
+      this.copySourceBtn.addEventListener('click', () => {
+        if (this.copySourceBtn.classList.contains('disabled')) return;
+
+        this.switchToViewer('simple');
+      });
+    }
+  }
+
+  switchViewHandler(e) {
+    const target = e.currentTarget;
+
+    e.preventDefault();
+
+    this.switchToViewer(target.getAttribute('data-viewer'));
+  }
+
+  toggleCopyButtonState() {
+    if (!this.copySourceBtn) return;
+
+    if (this.simpleViewer.getAttribute('data-loaded')) {
+      this.copySourceBtn.setAttribute('title', 'Copy source to clipboard');
+      this.copySourceBtn.classList.remove('disabled');
+    } else if (this.activeViewer == this.simpleViewer) {
+      this.copySourceBtn.setAttribute('title', 'Wait for the source to load to copy it to the clipboard');
+      this.copySourceBtn.classList.add('disabled');
+    } else {
+      this.copySourceBtn.setAttribute('title', 'Switch to the source to copy it to the clipboard');
+      this.copySourceBtn.classList.add('disabled');
+    }
+
+    $(this.copySourceBtn).tooltip('fixTitle');
+  }
+
+  loadViewer(viewerParam, resolve, reject) {
+    const viewer = viewerParam;
+    const url = viewer.getAttribute('data-url');
+
+    if (!url || viewer.getAttribute('data-loaded') || viewer.getAttribute('data-loading')) {
+      if (resolve) resolve();
+      return;
+    }
+
+    viewer.setAttribute('data-loading', 'true');
+
+    $.ajax({
+      url,
+      dataType: 'JSON',
+    })
+    .fail(() => {
+      if (reject) reject();
+    })
+    .done((data) => {
+      viewer.innerHTML = data.html;
+      $(viewer).syntaxHighlight();
+
+      viewer.setAttribute('data-loaded', 'true');
+
+      this.$blobContentHolder.trigger('highlight:line');
+
+      this.toggleCopyButtonState();
+
+      if (resolve) resolve();
+    });
+  }
+
+  switchToViewer(name) {
+    const newViewer = document.querySelector(`.blob-viewer[data-type='${name}']`);
+    if (this.activeViewer == newViewer) return;
+
+    const oldButton = document.querySelector('.js-blob-viewer-switcher.active')
+    const newButton = document.querySelector(`.js-blob-viewer-switcher[data-viewer='${name}']`);
+    const oldViewer = document.querySelector(`.blob-viewer:not([data-type='${name}'])`);
+
+    if (oldButton) {
+      oldButton.classList.remove('active');
+    }
+
+    if (newButton) {
+      newButton.classList.add('active');
+      newButton.blur();
+    }
+
+    if (oldViewer) {
+      oldViewer.classList.add('hidden');
+    }
+    
+    newViewer.classList.remove('hidden');
+
+    this.activeViewer = newViewer;
+
+    this.toggleCopyButtonState();
+
+    return new Promise((resolve, reject) => {
+      this.loadViewer(newViewer, resolve, reject);
+    })
+    .catch(() => {
+      new Flash('Error loading file');
+    });
+  }
+}
diff --git a/app/assets/javascripts/dispatcher.js b/app/assets/javascripts/dispatcher.js
index b20673cd03c..d3d75c4bf4a 100644
--- a/app/assets/javascripts/dispatcher.js
+++ b/app/assets/javascripts/dispatcher.js
@@ -48,6 +48,7 @@ import BlobForkSuggestion from './blob/blob_fork_suggestion';
 import UserCallout from './user_callout';
 import { ProtectedTagCreate, ProtectedTagEditList } from './protected_tags';
 import ShortcutsWiki from './shortcuts_wiki';
+import BlobViewer from './blob/viewer/index';
 
 const ShortcutsBlob = require('./shortcuts_blob');
 
@@ -299,6 +300,7 @@ const ShortcutsBlob = require('./shortcuts_blob');
           gl.TargetBranchDropDown.bootstrap();
           break;
         case 'projects:blob:show':
+          new BlobViewer();
           gl.TargetBranchDropDown.bootstrap();
           initBlob();
           break;
diff --git a/app/views/projects/blob/show.html.haml b/app/views/projects/blob/show.html.haml
index b9b3f3ec7a3..67f57b5e4b9 100644
--- a/app/views/projects/blob/show.html.haml
+++ b/app/views/projects/blob/show.html.haml
@@ -2,6 +2,9 @@
 - page_title @blob.path, @ref
 = render "projects/commits/head"
 
+- content_for :page_specific_javascripts do
+  = page_specific_javascript_bundle_tag('blob')
+
 %div{ class: container_class }
   = render 'projects/last_push'