diff --git a/swh/web/assets/src/bundles/webapp/webapp-utils.js b/swh/web/assets/src/bundles/webapp/webapp-utils.js
index 68e777d0..50f2d5ed 100644
--- a/swh/web/assets/src/bundles/webapp/webapp-utils.js
+++ b/swh/web/assets/src/bundles/webapp/webapp-utils.js
@@ -1,195 +1,207 @@
 import objectFitImages from 'object-fit-images';
 import {Layout} from 'admin-lte';
 import {selectText} from 'utils/functions';
 
 let collapseSidebar = false;
 let previousSidebarState = localStorage.getItem('swh-sidebar-collapsed');
 if (previousSidebarState !== undefined) {
   collapseSidebar = JSON.parse(previousSidebarState);
 }
 
 // adapt implementation of fixLayoutHeight from admin-lte
 Layout.prototype.fixLayoutHeight = () => {
   let heights = {
     window: $(window).height(),
     header: $('.main-header').outerHeight(),
     footer: $('.footer').outerHeight(),
     sidebar: $('.main-sidebar').height(),
     topbar: $('.swh-top-bar').height()
   };
   let offset = 10;
   $('.content-wrapper').css('min-height', heights.window - heights.topbar - heights.header - heights.footer - offset);
   $('.main-sidebar').css('min-height', heights.window - heights.topbar - heights.header - heights.footer - offset);
 };
 
 $(document).on('DOMContentLoaded', () => {
   // restore previous sidebar state (collapsed/expanded)
   if (collapseSidebar) {
     // hack to avoid animated transition for collapsing sidebar
     // when loading a page
     let sidebarTransition = $('.main-sidebar, .main-sidebar:before').css('transition');
     let sidebarEltsTransition = $('.sidebar .nav-link p, .main-sidebar .brand-text, .sidebar .user-panel .info').css('transition');
     $('.main-sidebar, .main-sidebar:before').css('transition', 'none');
     $('.sidebar .nav-link p, .main-sidebar .brand-text, .sidebar .user-panel .info').css('transition', 'none');
     $('body').addClass('sidebar-collapse');
     $('.swh-words-logo-swh').css('visibility', 'visible');
     // restore transitions for user navigation
     setTimeout(() => {
       $('.main-sidebar, .main-sidebar:before').css('transition', sidebarTransition);
       $('.sidebar .nav-link p, .main-sidebar .brand-text, .sidebar .user-panel .info').css('transition', sidebarEltsTransition);
     });
   }
 });
 
 $(document).on('collapsed.lte.pushmenu', event => {
   if ($('body').width() > 980) {
     $('.swh-words-logo-swh').css('visibility', 'visible');
   }
 });
 
 $(document).on('shown.lte.pushmenu', event => {
   $('.swh-words-logo-swh').css('visibility', 'hidden');
 });
 
 function ensureNoFooterOverflow() {
   $('body').css('padding-bottom', $('footer').outerHeight() + 'px');
 }
 
 $(document).ready(() => {
   // redirect to last browse page if any when clicking on the 'Browse' entry
   // in the sidebar
   $(`.swh-browse-link`).click(event => {
     let lastBrowsePage = sessionStorage.getItem('last-browse-page');
     if (lastBrowsePage) {
       event.preventDefault();
       window.location = lastBrowsePage;
     }
   });
 
   // ensure footer do not overflow main content for mobile devices
   // or after resizing the browser window
   ensureNoFooterOverflow();
   $(window).resize(function() {
     ensureNoFooterOverflow();
     if ($('body').hasClass('sidebar-collapse') && $('body').width() > 980) {
       $('.swh-words-logo-swh').css('visibility', 'visible');
     }
   });
   // activate css polyfill 'object-fit: contain' in old browsers
   objectFitImages();
 
   // reparent the modals to the top navigation div in order to be able
   // to display them
   $('.swh-browse-top-navigation').append($('.modal'));
 
   let selectedCode = null;
 
   function getCodeOrPreEltUnderPointer(e) {
     let elts = document.elementsFromPoint(e.clientX, e.clientY);
     for (let elt of elts) {
       if (elt.nodeName === 'CODE' || elt.nodeName === 'PRE') {
         return elt;
       }
     }
     return null;
   }
 
   // click handler to set focus on code block for copy
   $(document).click(e => {
     selectedCode = getCodeOrPreEltUnderPointer(e);
   });
 
   function selectCode(event, selectedCode) {
     if (selectedCode) {
       let hljsLnCodeElts = $(selectedCode).find('.hljs-ln-code');
       if (hljsLnCodeElts.length) {
         selectText(hljsLnCodeElts[0], hljsLnCodeElts[hljsLnCodeElts.length - 1]);
       } else {
         selectText(selectedCode.firstChild, selectedCode.lastChild);
       }
       event.preventDefault();
     }
   }
 
   // select the whole text of focused code block when user
   // double clicks or hits Ctrl+A
   $(document).dblclick(e => {
     if ((e.ctrlKey || e.metaKey)) {
       selectCode(e, getCodeOrPreEltUnderPointer(e));
     }
   });
 
   $(document).keydown(e => {
     if ((e.ctrlKey || e.metaKey) && e.key === 'a') {
       selectCode(e, selectedCode);
     }
   });
+
+  // show/hide back-to-top button
+  let scrollThreshold = 0;
+  scrollThreshold += $('.swh-top-bar').height() || 0;
+  scrollThreshold += $('.navbar').height() || 0;
+  $(window).scroll(() => {
+    if ($(window).scrollTop() > scrollThreshold) {
+      $('#back-to-top').css('display', 'block');
+    } else {
+      $('#back-to-top').css('display', 'none');
+    }
+  });
 });
 
 export function initPage(page) {
 
   $(document).ready(() => {
     // set relevant sidebar link to page active
     $(`.swh-${page}-item`).addClass('active');
     $(`.swh-${page}-link`).addClass('active');
 
     // triggered when unloading the current page
     $(window).on('unload', () => {
       // backup sidebar state (collapsed/expanded)
       let sidebarCollapsed = $('body').hasClass('sidebar-collapse');
       localStorage.setItem('swh-sidebar-collapsed', JSON.stringify(sidebarCollapsed));
       // backup current browse page
       if (page === 'browse') {
         sessionStorage.setItem('last-browse-page', window.location);
       }
     });
 
   });
 }
 
 export function showModalMessage(title, message) {
   $('#swh-web-modal-message .modal-title').text(title);
   $('#swh-web-modal-message .modal-content p').text(message);
   $('#swh-web-modal-message').modal('show');
 }
 
 export function showModalConfirm(title, message, callback) {
   $('#swh-web-modal-confirm .modal-title').text(title);
   $('#swh-web-modal-confirm .modal-content p').text(message);
   $('#swh-web-modal-confirm #swh-web-modal-confirm-ok-btn').bind('click', () => {
     callback();
     $('#swh-web-modal-confirm').modal('hide');
     $('#swh-web-modal-confirm #swh-web-modal-confirm-ok-btn').unbind('click');
   });
   $('#swh-web-modal-confirm').modal('show');
 }
 
 let swhObjectIcons;
 
 export function setSwhObjectIcons(icons) {
   swhObjectIcons = icons;
 }
 
 export function getSwhObjectIcon(swhObjectType) {
   return swhObjectIcons[swhObjectType];
 }
 
 let reCaptchaActivated;
 
 export function setReCaptchaActivated(activated) {
   reCaptchaActivated = activated;
 }
 
 export function isReCaptchaActivated() {
   return reCaptchaActivated;
 }
 
 let browsedSwhObjectMetadata = {};
 
 export function setBrowsedSwhObjectMetadata(metadata) {
   browsedSwhObjectMetadata = metadata;
 }
 
 export function getBrowsedSwhObjectMetadata() {
   return browsedSwhObjectMetadata;
 }
diff --git a/swh/web/assets/src/bundles/webapp/webapp.css b/swh/web/assets/src/bundles/webapp/webapp.css
index da58ee86..de7170cc 100644
--- a/swh/web/assets/src/bundles/webapp/webapp.css
+++ b/swh/web/assets/src/bundles/webapp/webapp.css
@@ -1,489 +1,489 @@
 /**
  * Copyright (C) 2018-2019  The Software Heritage developers
  * See the AUTHORS file at the top-level directory of this distribution
  * License: GNU Affero General Public License version 3, or any later version
  * See top-level LICENSE file for more information
  */
 
 html {
     height: 100%;
     overflow-x: hidden;
 }
 
 body {
     min-height: 100%;
     margin: 0;
     position: relative;
     padding-bottom: 120px;
 }
 
 a:active,
 a.active {
     outline: none;
 }
 
 code {
     background-color: #f9f2f4;
 }
 
 pre code {
     background-color: transparent;
 }
 
 footer {
     background-color: #262626;
     color: #fff;
     font-size: 0.8rem;
     position: absolute;
     bottom: 0;
     width: 100%;
     padding-top: 20px;
     padding-bottom: 20px;
 }
 
 footer a,
 footer a:visited,
 footer a:hover {
     color: #fecd1b;
 }
 
 footer a:hover {
     text-decoration: underline;
 }
 
 .link-color {
     color: #fecd1b;
 }
 
 pre {
     background-color: #f5f5f5;
     border: 1px solid #ccc;
     border-radius: 4px;
     padding: 9.5px;
     font-size: 0.8rem;
 }
 
 .btn.active {
     background-color: #e7e7e7;
 }
 
 .card {
     margin-bottom: 5px !important;
     overflow-x: auto;
 }
 
 .navbar-brand {
     padding: 5px;
     margin-right: 0;
 }
 
 .table {
     margin-bottom: 0;
 }
 
 .swh-table thead {
     background-color: #f2f4f5;
     border-top: 1px solid rgba(0, 0, 0, 0.2);
     font-weight: normal;
 }
 
 .swh-table-striped th {
     border-top: none;
 }
 
 .swh-table-striped tbody tr:nth-child(even) {
     background-color: #f2f4f5;
 }
 
 .swh-table-striped tbody tr:nth-child(odd) {
     background-color: #fff;
 }
 
 .swh-web-app-link a {
     text-decoration: none;
     border: none;
 }
 
 .swh-web-app-link:hover {
     background-color: #efeff2;
 }
 
 .table > thead > tr > th {
     border-top: none;
     border-bottom: 1px solid #e20026;
 }
 
 .table > tbody > tr > td {
     border-style: none;
 }
 
 .sitename .first-word,
 .sitename .second-word {
     color: rgba(0, 0, 0, 0.75);
     font-weight: normal;
     font-size: 1.2rem;
 }
 
 .sitename .first-word {
     font-family: 'Alegreya Sans', sans-serif;
 }
 
 .sitename .second-word {
     font-family: 'Alegreya', serif;
 }
 
 .swh-counter {
     font-size: 150%;
 }
 
 .swh-http-error {
     margin: 0 auto;
     text-align: center;
 }
 
 .swh-http-error-head {
     color: #2d353c;
     font-size: 30px;
 }
 
 .swh-http-error-code {
     bottom: 60%;
     color: #2d353c;
     font-size: 96px;
     line-height: 80px;
     margin-bottom: 10px !important;
 }
 
 .swh-http-error-desc {
     font-size: 12px;
     color: #647788;
     text-align: center;
 }
 
 .swh-http-error-desc pre {
     display: inline-block;
     text-align: left;
     max-width: 800px;
     white-space: pre-wrap;
 }
 
 .popover {
     max-width: 100%;
     z-index: 2000;
 }
 
 .modal {
     text-align: center;
     padding: 0 !important;
 }
 
 .modal::before {
     content: '';
     display: inline-block;
     height: 100%;
     vertical-align: middle;
     margin-right: -4px;
 }
 
 .modal-dialog {
     display: inline-block;
     text-align: left;
     vertical-align: middle;
 }
 
 .dropdown-submenu {
     position: relative;
 }
 
 .dropdown-submenu .dropdown-menu {
     top: 0;
     left: -100%;
     margin-top: -5px;
     margin-left: -2px;
 }
 
 .dropdown-item:hover,
 .dropdown-item:focus {
     background-color: rgba(0, 0, 0, 0.1);
 }
 
 a.dropdown-left::before {
     content: "\f0d9";
     font-family: 'FontAwesome';
     display: block;
     width: 20px;
     height: 20px;
     float: left;
     margin-left: 0;
 }
 
 #swh-navbar {
     border-top-style: none;
     border-left-style: none;
     border-right-style: none;
     border-bottom-style: solid;
     border-bottom-width: 5px;
     border-image: linear-gradient(to right, rgb(226, 0, 38) 0%, rgb(254, 205, 27) 100%) 1 1 1 1;
     width: 100%;
     padding: 5px;
     margin-bottom: 10px;
     margin-top: 30px;
     justify-content: normal;
     flex-wrap: nowrap;
     height: 72px;
     overflow: hidden;
 }
 
 #back-to-top {
-    display: initial;
+    display: none;
     position: fixed;
     bottom: 30px;
     right: 30px;
     z-index: 10;
 }
 
 #back-to-top a img {
     display: block;
     width: 32px;
     height: 32px;
     background-size: 32px 32px;
     text-indent: -999px;
     overflow: hidden;
 }
 
 .swh-top-bar {
     direction: ltr;
     height: 30px;
     position: fixed;
     top: 0;
     left: 0;
     width: 100%;
     z-index: 99999;
     background-color: #262626;
     color: #fff;
     text-align: center;
     font-size: 14px;
 }
 
 .swh-top-bar ul {
     margin-top: 4px;
     padding-left: 0;
     white-space: nowrap;
 }
 
 .swh-top-bar li {
     display: inline-block;
     margin-left: 10px;
     margin-right: 10px;
 }
 
 .swh-top-bar a,
 .swh-top-bar a:visited {
     color: white;
 }
 
 .swh-top-bar a.swh-current-site,
 .swh-top-bar a.swh-current-site:visited {
     color: #fecd1b;
 }
 
 .swh-position-right {
     position: absolute;
     right: 0;
 }
 
 .swh-donate-link {
     border: 1px solid #fecd1b;
     background-color: #e20026;
     color: white !important;
     padding: 3px;
     border-radius: 3px;
 }
 
 .swh-navbar-content h4 {
     padding-top: 7px;
 }
 
 .swh-navbar-content .bread-crumbs {
     display: block;
     margin-left: -40px;
 }
 
 .swh-navbar-content .bread-crumbs li.bc-no-root {
     padding-top: 7px;
 }
 
 .main-sidebar {
     margin-top: 30px;
 }
 
 .content-wrapper {
     background: none;
 }
 
 .brand-image {
     max-height: 40px;
 }
 
 .brand-link {
     padding-top: 18.5px;
     padding-bottom: 18px;
     padding-left: 4px;
     border-bottom: 5px solid #e20026 !important;
 }
 
 .navbar-header a,
 ul.dropdown-menu a,
 ul.navbar-nav a,
 ul.nav-sidebar a {
     border-bottom-style: none;
     color: #323232;
 }
 
 .swh-sidebar .nav-link.active {
     color: #323232 !important;
     background-color: #e7e7e7 !important;
 }
 
 .swh-image-error {
     width: 80px;
     height: auto;
 }
 
 @media (max-width: 600px) {
     .swh-image-error {
         width: 40px;
         height: auto;
     }
 
     .swh-navbar-content h4 {
         font-size: 1rem;
     }
 
     .swh-donate-link {
         display: none;
     }
 }
 
 .form-check-label {
     padding-top: 4px;
 }
 
 .swh-id-option {
     display: inline-block;
     margin-right: 5px;
     line-height: 1rem;
 }
 
 .nav-pills .nav-link:not(.active):hover {
     color: rgba(0, 0, 0, 0.55);
 }
 
 .swh-heading-color {
     color: #e20026 !important;
 }
 
 .sidebar-mini.sidebar-collapse .main-sidebar:hover {
     width: 4.6rem;
 }
 
 .sidebar-mini.sidebar-collapse .main-sidebar:hover .user-panel > .info,
 .sidebar-mini.sidebar-collapse .main-sidebar:hover .nav-sidebar .nav-link p,
 .sidebar-mini.sidebar-collapse .main-sidebar:hover .brand-text {
     visibility: hidden !important;
 }
 
 .sidebar .nav-link p,
 .main-sidebar .brand-text,
 .sidebar .user-panel .info {
     transition: none;
 }
 
 .sidebar-mini.sidebar-mini.sidebar-collapse .sidebar {
     padding-right: 0;
 }
 
 .swh-words-logo {
     position: absolute;
     top: 0;
     left: 0;
     width: 73px;
     height: 73px;
     text-align: center;
     font-size: 10pt;
     color: rgba(0, 0, 0, 0.75);
 }
 
 .swh-words-logo:hover {
     text-decoration: none;
 }
 
 .swh-words-logo-swh {
     line-height: 1;
     padding-top: 13px;
     visibility: hidden;
 }
 
 hr.swh-faded-line {
     border: 0;
     height: 1px;
     background-image: linear-gradient(to left, #f0f0f0, #8c8b8b, #f0f0f0);
 }
 
 .swh-readme-txt pre {
     background: none;
     border: none;
 }
 
 .swh-coverage-col {
     padding-left: 10px;
     padding-right: 10px;
 }
 
 .swh-coverage {
     height: calc(65px + 1em);
     padding-top: 0.3rem;
     border: none;
 }
 
 .swh-coverage a {
     text-decoration: none;
 }
 
 .swh-coverage-logo {
     display: block;
     width: 100%;
     height: 50px;
     margin-left: auto;
     margin-right: auto;
     object-fit: contain;
 
     /* polyfill for old browsers, see https://github.com/bfred-it/object-fit-images */
     font-family: 'object-fit: contain;';
 }
 
 .swh-coverage-list {
     width: 100%;
     height: 320px;
     border: none;
 }
 
 tr.swh-tr-hover-highlight:hover td {
     background: #ededed;
 }
 
 tr.swh-api-doc-route a {
     text-decoration: none;
 }
 
 .swh-apidoc .col {
     margin: 10px;
 }
 
 a.toggle-col {
     text-decoration: none;
 }
 
 a.toggle-col.col-hidden {
     text-decoration: line-through;
 }