diff --git a/searx/static/themes/__common__/js/image_layout.js b/searx/static/themes/__common__/js/image_layout.js
index be4fe84e0..e37058dfa 100644
--- a/searx/static/themes/__common__/js/image_layout.js
+++ b/searx/static/themes/__common__/js/image_layout.js
@@ -22,7 +22,7 @@
 
 
 (function (w, d) {
-  function ImageLayout(container_selector, results_selector, img_selector, verticalMargin, horizontalMargin, maxHeight) {
+  function ImageLayout (container_selector, results_selector, img_selector, verticalMargin, horizontalMargin, maxHeight) {
     this.container_selector = container_selector;
     this.results_selector = results_selector;
     this.img_selector = img_selector;
@@ -57,7 +57,7 @@
       }
     }
 
-    return (width - images.length * this.verticalMargin) / r; //have to round down because Firefox will automatically roundup value with number of decimals > 3
+    return (width - images.length * this.verticalMargin) / r; // have to round down because Firefox will automatically roundup value with number of decimals > 3
   };
 
   ImageLayout.prototype._setSize = function (images, height) {
@@ -147,12 +147,12 @@
     var results_nodes = d.querySelectorAll(this.results_selector);
     var results_length = results_nodes.length;
 
-    function img_load_error(event) {
+    function img_load_error (event) {
       // console.log("ERROR can't load: " + event.originalTarget.src);
       event.originalTarget.src = w.searxng.static_path + w.searxng.theme.img_load_error;
     }
 
-    function throttleAlign() {
+    function throttleAlign () {
       if (obj.isAlignDone) {
         obj.isAlignDone = false;
         setTimeout(function () {
diff --git a/searx/static/themes/simple/gruntfile.js b/searx/static/themes/simple/gruntfile.js
index 928b92d82..aac1217ea 100644
--- a/searx/static/themes/simple/gruntfile.js
+++ b/searx/static/themes/simple/gruntfile.js
@@ -1,6 +1,6 @@
-/*jshint esversion: 6 */
+/* jshint esversion: 6 */
 
-module.exports = function(grunt) {
+module.exports = function (grunt) {
 
   const eachAsync = require('each-async');
 
@@ -113,7 +113,7 @@ module.exports = function(grunt) {
             new (require('less-plugin-clean-css'))()
           ],
           sourceMap: true,
-          sourceMapURL: (name) => { const s = name.split('/'); return s[s.length - 1] + '.map';},
+          sourceMapURL: (name) => { const s = name.split('/'); return s[s.length - 1] + '.map'; },
           outputSourceFiles: true,
         },
         files: {
@@ -178,37 +178,37 @@ module.exports = function(grunt) {
     },
   });
 
-  grunt.registerMultiTask('svg2jinja', 'Create Jinja2 macro', function() {
+  grunt.registerMultiTask('svg2jinja', 'Create Jinja2 macro', function () {
     const ejs = require('ejs'), svgo = require('svgo');
     const icons = {}
-    for(const iconName in this.data.src) {
-        const svgFileName = this.data.src[iconName];
-        try {
-            const svgContent = grunt.file.read(svgFileName, { encoding: 'utf8' })
-            const svgoResult = svgo.optimize(svgContent, {
-              path: svgFileName,
-              multipass: true,
-              plugins: [
-                {
-                  name: "removeTitle",
-                },
-                {
-                  name: "removeXMLNS",
-                },
-                {
-                  name: "addAttributesToSVGElement",
-                  params: {
-                    attributes: [
-                      { "aria-hidden": "true" }
-                    ]
-                  }
-                }
-              ]
-            });
-            icons[iconName] = svgoResult.data.replace("'", "\\'");
-        } catch (err) {
-          grunt.log.error(err);
-        }
+    for (const iconName in this.data.src) {
+      const svgFileName = this.data.src[iconName];
+      try {
+        const svgContent = grunt.file.read(svgFileName, { encoding: 'utf8' })
+        const svgoResult = svgo.optimize(svgContent, {
+          path: svgFileName,
+          multipass: true,
+          plugins: [
+            {
+              name: "removeTitle",
+            },
+            {
+              name: "removeXMLNS",
+            },
+            {
+              name: "addAttributesToSVGElement",
+              params: {
+                attributes: [
+                  { "aria-hidden": "true" }
+                ]
+              }
+            }
+          ]
+        });
+        icons[iconName] = svgoResult.data.replace("'", "\\'");
+      } catch (err) {
+        grunt.log.error(err);
+      }
     }
     const template = `{# this file was generated by searx/static/themes/simple/gruntfile.js #}
 {%- set icons = {
diff --git a/searx/static/themes/simple/src/js/head/00_init.js b/searx/static/themes/simple/src/js/head/00_init.js
index dab0e368a..073371ce6 100644
--- a/searx/static/themes/simple/src/js/head/00_init.js
+++ b/searx/static/themes/simple/src/js/head/00_init.js
@@ -5,36 +5,36 @@
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 /* global DocumentTouch:readonly */
-(function(w, d) {
-    'use strict';
+(function (w, d) {
+  'use strict';
 
-    // add data- properties
-    var script = d.currentScript  || (function() {
-        var scripts = d.getElementsByTagName('script');
-        return scripts[scripts.length - 1];
-    })();
+  // add data- properties
+  var script = d.currentScript  || (function () {
+    var scripts = d.getElementsByTagName('script');
+    return scripts[scripts.length - 1];
+  })();
 
-    // try to detect touch screen
-    w.searxng = {
-        touch: (("ontouchstart" in w) || w.DocumentTouch && document instanceof DocumentTouch) || false,
-        method: script.getAttribute('data-method'),
-        autocompleter: script.getAttribute('data-autocompleter') === 'true',
-        search_on_category_select: script.getAttribute('data-search-on-category-select') === 'true',
-        infinite_scroll: script.getAttribute('data-infinite-scroll') === 'true',
-        hotkeys: script.getAttribute('data-hotkeys') === 'true',
-        static_path: script.getAttribute('data-static-path'),
-        translations: JSON.parse(script.getAttribute('data-translations')),
-        theme : {
-            // image that is displayed if load of <img src='...'> failed
-            img_load_error: 'img/img_load_error.svg'
-        }
-    };
-
-    // update the css
-    var hmtlElement = d.getElementsByTagName("html")[0];
-    hmtlElement.classList.remove('no-js');
-    hmtlElement.classList.add('js');
-    if (w.searxng.touch) {
-        hmtlElement.classList.add('touch');
+  // try to detect touch screen
+  w.searxng = {
+    touch: (("ontouchstart" in w) || w.DocumentTouch && document instanceof DocumentTouch) || false,
+    method: script.getAttribute('data-method'),
+    autocompleter: script.getAttribute('data-autocompleter') === 'true',
+    search_on_category_select: script.getAttribute('data-search-on-category-select') === 'true',
+    infinite_scroll: script.getAttribute('data-infinite-scroll') === 'true',
+    hotkeys: script.getAttribute('data-hotkeys') === 'true',
+    static_path: script.getAttribute('data-static-path'),
+    translations: JSON.parse(script.getAttribute('data-translations')),
+    theme: {
+      // image that is displayed if load of <img src='...'> failed
+      img_load_error: 'img/img_load_error.svg'
     }
+  };
+
+  // update the css
+  var hmtlElement = d.getElementsByTagName("html")[0];
+  hmtlElement.classList.remove('no-js');
+  hmtlElement.classList.add('js');
+  if (w.searxng.touch) {
+    hmtlElement.classList.add('touch');
+  }
 })(window, document);
\ No newline at end of file
diff --git a/searx/static/themes/simple/src/js/main/00_toolkit.js b/searx/static/themes/simple/src/js/main/00_toolkit.js
index 7dc50108b..c5b7fe578 100644
--- a/searx/static/themes/simple/src/js/main/00_toolkit.js
+++ b/searx/static/themes/simple/src/js/main/00_toolkit.js
@@ -4,7 +4,7 @@
  * (C) Copyright Contributors to the searx project (2014 - 2021).
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
-window.searxng = (function(w, d) {
+window.searxng = (function (w, d) {
 
   'use strict';
 
@@ -13,12 +13,12 @@ window.searxng = (function(w, d) {
 
   // from https://plainjs.com/javascript/events/live-binding-event-handlers-14/
   if (w.Element) {
-    (function(ElementPrototype) {
+    (function (ElementPrototype) {
       ElementPrototype.matches = ElementPrototype.matches ||
       ElementPrototype.matchesSelector ||
       ElementPrototype.webkitMatchesSelector ||
       ElementPrototype.msMatchesSelector ||
-      function(selector) {
+      function (selector) {
         var node = this, nodes = (node.parentNode || node.document).querySelectorAll(selector), i = -1;
         while (nodes[++i] && nodes[i] != node);
         return !!nodes[i];
@@ -26,7 +26,7 @@ window.searxng = (function(w, d) {
     })(Element.prototype);
   }
 
-  function callbackSafe(callback, el, e) {
+  function callbackSafe (callback, el, e) {
     try {
       callback.call(el, e);
     } catch (exception) {
@@ -36,14 +36,14 @@ window.searxng = (function(w, d) {
 
   var searxng = window.searxng || {};
 
-  searxng.on = function(obj, eventType, callback, useCapture) {
+  searxng.on = function (obj, eventType, callback, useCapture) {
     useCapture = useCapture || false;
     if (typeof obj !== 'string') {
       // obj HTMLElement, HTMLDocument
       obj.addEventListener(eventType, callback, useCapture);
     } else {
       // obj is a selector
-      d.addEventListener(eventType, function(e) {
+      d.addEventListener(eventType, function (e) {
         var el = e.target || e.srcElement, found = false;
         while (el && el.matches && el !== d && !(found = el.matches(obj))) el = el.parentElement;
         if (found) callbackSafe(callback, el, e);
@@ -51,7 +51,7 @@ window.searxng = (function(w, d) {
     }
   };
 
-  searxng.ready = function(callback) {
+  searxng.ready = function (callback) {
     if (document.readyState != 'loading') {
       callback.call(w);
     } else {
@@ -59,20 +59,20 @@ window.searxng = (function(w, d) {
     }
   };
 
-  searxng.http = function(method, url) {
+  searxng.http = function (method, url) {
     var req = new XMLHttpRequest(),
-    resolve = function() {},
-    reject = function() {},
-    promise = {
-      then: function(callback) { resolve = callback; return promise; },
-      catch: function(callback) { reject = callback; return promise; }
-    };
+      resolve = function () {},
+      reject = function () {},
+      promise = {
+        then: function (callback) { resolve = callback; return promise; },
+        catch: function (callback) { reject = callback; return promise; }
+      };
 
     try {
       req.open(method, url, true);
 
       // On load
-      req.onload = function() {
+      req.onload = function () {
         if (req.status == 200) {
           resolve(req.response, req.responseType);
         } else {
@@ -81,11 +81,11 @@ window.searxng = (function(w, d) {
       };
 
       // Handle network errors
-      req.onerror = function() {
+      req.onerror = function () {
         reject(Error("Network Error"));
       };
 
-      req.onabort = function() {
+      req.onabort = function () {
         reject(Error("Transaction is aborted"));
       };
 
@@ -98,10 +98,10 @@ window.searxng = (function(w, d) {
     return promise;
   };
 
-  searxng.loadStyle = function(src) {
+  searxng.loadStyle = function (src) {
     var path = searxng.static_path + src,
-    id = "style_" + src.replace('.', '_'),
-    s = d.getElementById(id);
+      id = "style_" + src.replace('.', '_'),
+      s = d.getElementById(id);
     if (s === null) {
       s = d.createElement('link');
       s.setAttribute('id', id);
@@ -112,16 +112,16 @@ window.searxng = (function(w, d) {
     }
   };
 
-  searxng.loadScript = function(src, callback) {
+  searxng.loadScript = function (src, callback) {
     var path = searxng.static_path + src,
-    id = "script_" + src.replace('.', '_'),
-    s = d.getElementById(id);
+      id = "script_" + src.replace('.', '_'),
+      s = d.getElementById(id);
     if (s === null) {
       s = d.createElement('script');
       s.setAttribute('id', id);
       s.setAttribute('src', path);
       s.onload = callback;
-      s.onerror = function() {
+      s.onerror = function () {
         s.setAttribute('error', '1');
       };
       d.body.appendChild(s);
@@ -140,13 +140,13 @@ window.searxng = (function(w, d) {
     referenceNode.parentNode.insertBefore(newNode, referenceNode);
   };
 
-  searxng.insertAfter = function(newNode, referenceNode) {
+  searxng.insertAfter = function (newNode, referenceNode) {
     referenceNode.parentNode.insertAfter(newNode, referenceNode.nextSibling);
-  };  
+  };
 
-  searxng.on('.close', 'click', function() {
+  searxng.on('.close', 'click', function () {
     this.parentNode.classList.add('invisible');
   });
-  
+
   return searxng;
 })(window, document);
diff --git a/searx/static/themes/simple/src/js/main/keyboard.js b/searx/static/themes/simple/src/js/main/keyboard.js
index 788d289ef..a8ab7222f 100644
--- a/searx/static/themes/simple/src/js/main/keyboard.js
+++ b/searx/static/themes/simple/src/js/main/keyboard.js
@@ -1,9 +1,9 @@
 /* SPDX-License-Identifier: AGPL-3.0-or-later */
-/*global searxng*/
+/* global searxng */
 
-searxng.ready(function() {
+searxng.ready(function () {
 
-  function isElementInDetail(el) {
+  function isElementInDetail (el) {
     while (el !== undefined) {
       if (el.classList.contains('detail')) {
         return true;
@@ -18,7 +18,7 @@ searxng.ready(function() {
     return false;
   }
 
-  function getResultElement(el) {
+  function getResultElement (el) {
     while (el !== undefined) {
       if (el.classList.contains('result')) {
         return el;
@@ -28,11 +28,11 @@ searxng.ready(function() {
     return undefined;
   }
 
-  function isImageResult(resultElement) {
+  function isImageResult (resultElement) {
     return resultElement && resultElement.classList.contains('result-images');
   }
 
-  searxng.on('.result', 'click', function(e) {
+  searxng.on('.result', 'click', function (e) {
     if (!isElementInDetail(e.target)) {
       highlightResult(this)(true);
       let resultElement = getResultElement(e.target);
@@ -43,7 +43,7 @@ searxng.ready(function() {
     }
   });
 
-  searxng.on('.result a', 'focus', function(e) {
+  searxng.on('.result a', 'focus', function (e) {
     if (!isElementInDetail(e.target)) {
       let resultElement = getResultElement(e.target);
       if (resultElement && resultElement.getAttribute("data-vim-selected") === null) {
@@ -155,7 +155,7 @@ searxng.ready(function() {
   };
 
   if (searxng.hotkeys) {
-    searxng.on(document, "keydown", function(e) {
+    searxng.on(document, "keydown", function (e) {
       // check for modifiers so we don't break browser's hotkeys
       if (Object.prototype.hasOwnProperty.call(vimKeys, e.keyCode) && !e.ctrlKey && !e.altKey && !e.shiftKey && !e.metaKey) {
         var tagName = e.target.tagName.toLowerCase();
@@ -171,10 +171,10 @@ searxng.ready(function() {
     });
   }
 
-  function highlightResult(which) {
-    return function(noScroll) {
+  function highlightResult (which) {
+    return function (noScroll) {
       var current = document.querySelector('.result[data-vim-selected]'),
-      effectiveWhich = which;
+        effectiveWhich = which;
       if (current === null) {
         // no selection : choose the first one
         current = document.querySelector('.result');
@@ -194,7 +194,7 @@ searxng.ready(function() {
         next = effectiveWhich;
       } else {
         switch (effectiveWhich) {
-          case 'visible':
+        case 'visible':
           var top = document.documentElement.scrollTop || document.body.scrollTop;
           var bot = top + document.documentElement.clientHeight;
 
@@ -208,24 +208,24 @@ searxng.ready(function() {
             }
           }
           break;
-          case 'down':
+        case 'down':
           next = current.nextElementSibling;
           if (next === null) {
             next = results[0];
           }
           break;
-          case 'up':
+        case 'up':
           next = current.previousElementSibling;
           if (next === null) {
             next = results[results.length - 1];
           }
           break;
-          case 'bottom':
+        case 'bottom':
           next = results[results.length - 1];
           break;
-          case 'top':
+        case 'top':
           /* falls through */
-          default:
+        default:
           next = results[0];
         }
       }
@@ -244,11 +244,11 @@ searxng.ready(function() {
     };
   }
 
-  function reloadPage() {
+  function reloadPage () {
     document.location.reload(true);
   }
 
-  function removeFocus(e) {
+  function removeFocus (e) {
     const tagName = e.target.tagName.toLowerCase();
     if (document.activeElement && (tagName === 'input' || tagName === 'select' || tagName === 'textarea')) {
       document.activeElement.blur();
@@ -257,8 +257,8 @@ searxng.ready(function() {
     }
   }
 
-  function pageButtonClick(css_selector) {
-    return function() {
+  function pageButtonClick (css_selector) {
+    return function () {
       var button = document.querySelector(css_selector);
       if (button) {
         button.click();
@@ -266,24 +266,24 @@ searxng.ready(function() {
     };
   }
 
-  function GoToNextPage() {
+  function GoToNextPage () {
     return pageButtonClick('nav#pagination .next_page button[type="submit"]');
   }
 
-  function GoToPreviousPage() {
+  function GoToPreviousPage () {
     return pageButtonClick('nav#pagination .previous_page button[type="submit"]');
   }
 
-  function scrollPageToSelected() {
+  function scrollPageToSelected () {
     var sel = document.querySelector('.result[data-vim-selected]');
     if (sel === null) {
       return;
     }
     var wtop = document.documentElement.scrollTop || document.body.scrollTop,
-    wheight = document.documentElement.clientHeight,
-    etop = sel.offsetTop,
-    ebot = etop + sel.clientHeight,
-    offset = 120;
+      wheight = document.documentElement.clientHeight,
+      etop = sel.offsetTop,
+      ebot = etop + sel.clientHeight,
+      offset = 120;
     // first element ?
     if ((sel.previousElementSibling === null) && (ebot < wheight)) {
       // set to the top of page if the first element
@@ -301,27 +301,27 @@ searxng.ready(function() {
     }
   }
 
-  function scrollPage(amount) {
-    return function() {
+  function scrollPage (amount) {
+    return function () {
       window.scrollBy(0, amount);
       highlightResult('visible')();
     };
   }
 
-  function scrollPageTo(position, nav) {
-    return function() {
+  function scrollPageTo (position, nav) {
+    return function () {
       window.scrollTo(0, position);
       highlightResult(nav)();
     };
   }
 
-  function searchInputFocus() {
+  function searchInputFocus () {
     window.scrollTo(0, 0);
     document.querySelector('#q').focus();
   }
 
-  function openResult(newTab) {
-    return function() {
+  function openResult (newTab) {
+    return function () {
       var link = document.querySelector('.result[data-vim-selected] h3 a');
       if (link === null) {
         link = document.querySelector('.result[data-vim-selected] > a');
@@ -337,7 +337,7 @@ searxng.ready(function() {
     };
   }
 
-  function initHelpContent(divElement) {
+  function initHelpContent (divElement) {
     var categories = {};
 
     for (var k in vimKeys) {
@@ -346,7 +346,7 @@ searxng.ready(function() {
       categories[key.cat].push(key);
     }
 
-    var sorted = Object.keys(categories).sort(function(a, b) {
+    var sorted = Object.keys(categories).sort(function (a, b) {
       return categories[b].length - categories[a].length;
     });
 
@@ -386,23 +386,23 @@ searxng.ready(function() {
 
     html += '</table>';
 
-     divElement.innerHTML = html;
+    divElement.innerHTML = html;
   }
 
-  function toggleHelp() {
+  function toggleHelp () {
     var helpPanel = document.querySelector('#vim-hotkeys-help');
     if (helpPanel === undefined || helpPanel === null) {
-       // first call
+      // first call
       helpPanel = document.createElement('div');
-         helpPanel.id = 'vim-hotkeys-help';
-        helpPanel.className='dialog-modal';
+      helpPanel.id = 'vim-hotkeys-help';
+      helpPanel.className = 'dialog-modal';
+      initHelpContent(helpPanel);
       initHelpContent(helpPanel);
-			initHelpContent(helpPanel);					
       initHelpContent(helpPanel);
       var body = document.getElementsByTagName('body')[0];
       body.appendChild(helpPanel);
     } else {
-       // togggle hidden
+      // togggle hidden
       helpPanel.classList.toggle('invisible');
       return;
     }
diff --git a/searx/static/themes/simple/src/js/main/mapresult.js b/searx/static/themes/simple/src/js/main/mapresult.js
index 75d13b515..419bfa9fa 100644
--- a/searx/static/themes/simple/src/js/main/mapresult.js
+++ b/searx/static/themes/simple/src/js/main/mapresult.js
@@ -4,7 +4,7 @@
   'use strict';
 
   searxng.ready(function () {
-    searxng.on('.searxng_init_map', 'click', function(event) {
+    searxng.on('.searxng_init_map', 'click', function (event) {
       // no more request
       this.classList.remove("searxng_init_map");
 
@@ -17,9 +17,9 @@
       var map_geojson = JSON.parse(this.dataset.mapGeojson);
 
       searxng.loadStyle('css/leaflet.css');
-      searxng.loadScript('js/leaflet.js', function() {
+      searxng.loadScript('js/leaflet.js', function () {
         var map_bounds = null;
-        if(map_boundingbox) {
+        if (map_boundingbox) {
           var southWest = L.latLng(map_boundingbox[0], map_boundingbox[2]);
           var northEast = L.latLng(map_boundingbox[1], map_boundingbox[3]);
           map_bounds = L.latLngBounds(southWest, northEast);
@@ -28,26 +28,26 @@
         // init map
         var map = L.map(leaflet_target);
         // create the tile layer with correct attribution
-        var osmMapnikUrl='https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png';
-        var osmMapnikAttrib='Map data © <a href="https://openstreetmap.org">OpenStreetMap</a> contributors';
+        var osmMapnikUrl = 'https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png';
+        var osmMapnikAttrib = 'Map data © <a href="https://openstreetmap.org">OpenStreetMap</a> contributors';
         var osmMapnik = new L.TileLayer(osmMapnikUrl, {minZoom: 1, maxZoom: 19, attribution: osmMapnikAttrib});
-        var osmWikimediaUrl='https://maps.wikimedia.org/osm-intl/{z}/{x}/{y}.png';
+        var osmWikimediaUrl = 'https://maps.wikimedia.org/osm-intl/{z}/{x}/{y}.png';
         var osmWikimediaAttrib = 'Wikimedia maps | Maps data © <a href="https://openstreetmap.org">OpenStreetMap contributors</a>';
         var osmWikimedia = new L.TileLayer(osmWikimediaUrl, {minZoom: 1, maxZoom: 19, attribution: osmWikimediaAttrib});
         // init map view
-        if(map_bounds) {
+        if (map_bounds) {
           // TODO hack: https://github.com/Leaflet/Leaflet/issues/2021
           // Still useful ?
           setTimeout(function () {
             map.fitBounds(map_bounds, {
-              maxZoom:17
+              maxZoom: 17
             });
           }, 0);
         } else if (map_lon && map_lat) {
-          if(map_zoom) {
-            map.setView(new L.latLng(map_lat, map_lon),map_zoom);
+          if (map_zoom) {
+            map.setView(new L.latLng(map_lat, map_lon), map_zoom);
           } else {
-            map.setView(new L.latLng(map_lat, map_lon),8);
+            map.setView(new L.latLng(map_lat, map_lon), 8);
           }
         }
 
@@ -60,11 +60,11 @@
 
         L.control.layers(baseLayers).addTo(map);
 
-        if(map_geojson) {
+        if (map_geojson) {
           L.geoJson(map_geojson).addTo(map);
-        } /*else if(map_bounds) {
+        } /* else if(map_bounds) {
           L.rectangle(map_bounds, {color: "#ff7800", weight: 3, fill:false}).addTo(map);
-        }*/
+        } */
       });
 
       // this event occour only once per element
diff --git a/searx/static/themes/simple/src/js/main/preferences.js b/searx/static/themes/simple/src/js/main/preferences.js
index b19026a43..343f20826 100644
--- a/searx/static/themes/simple/src/js/main/preferences.js
+++ b/searx/static/themes/simple/src/js/main/preferences.js
@@ -1,28 +1,28 @@
 /* SPDX-License-Identifier: AGPL-3.0-or-later */
 (function (w, d, searxng) {
-    'use strict';
+  'use strict';
 
-    searxng.ready(function() {
-        let engine_descriptions = null;
-        function load_engine_descriptions() {
-            if (engine_descriptions == null) {
-                searxng.http("GET", "engine_descriptions.json").then(function(content) {
-                    engine_descriptions = JSON.parse(content);
-                    for (const [engine_name, description] of Object.entries(engine_descriptions)) {
-                        let elements = d.querySelectorAll('[data-engine-name="' + engine_name + '"] .engine-description');
-                        for(const element of elements) {
-                            let source = ' (<i>' + searxng.translations['Source'] + ':&nbsp;' + description[1] + '</i>)';
-                            element.innerHTML = description[0] + source;
-                        }
-                    }
-                });
+  searxng.ready(function () {
+    let engine_descriptions = null;
+    function load_engine_descriptions () {
+      if (engine_descriptions == null) {
+        searxng.http("GET", "engine_descriptions.json").then(function (content) {
+          engine_descriptions = JSON.parse(content);
+          for (const [engine_name, description] of Object.entries(engine_descriptions)) {
+            let elements = d.querySelectorAll('[data-engine-name="' + engine_name + '"] .engine-description');
+            for (const element of elements) {
+              let source = ' (<i>' + searxng.translations['Source'] + ':&nbsp;' + description[1] + '</i>)';
+              element.innerHTML = description[0] + source;
             }
-        }
+          }
+        });
+      }
+    }
 
-        if (d.querySelector('body[class="preferences_endpoint"]')) {
-            for(const el of d.querySelectorAll('[data-engine-name]')) {
-                searxng.on(el, 'mouseenter', load_engine_descriptions);
-            }
-        }
-    });
+    if (d.querySelector('body[class="preferences_endpoint"]')) {
+      for (const el of d.querySelectorAll('[data-engine-name]')) {
+        searxng.on(el, 'mouseenter', load_engine_descriptions);
+      }
+    }
+  });
 })(window, document, window.searxng);
diff --git a/searx/static/themes/simple/src/js/main/results.js b/searx/static/themes/simple/src/js/main/results.js
index e4b139fe0..b6b4d0834 100644
--- a/searx/static/themes/simple/src/js/main/results.js
+++ b/searx/static/themes/simple/src/js/main/results.js
@@ -1,12 +1,12 @@
 /* SPDX-License-Identifier: AGPL-3.0-or-later */
-(function(w, d, searxng) {
+(function (w, d, searxng) {
   'use strict';
 
-  searxng.ready(function() {
+  searxng.ready(function () {
     searxng.image_thumbnail_layout = new searxng.ImageLayout('#urls', '#urls .result-images', 'img.image_thumbnail', 14, 6, 200);
     searxng.image_thumbnail_layout.watch();
 
-    searxng.on('.btn-collapse', 'click', function() {
+    searxng.on('.btn-collapse', 'click', function () {
       var btnLabelCollapsed = this.getAttribute('data-btn-text-collapsed');
       var btnLabelNotCollapsed = this.getAttribute('data-btn-text-not-collapsed');
       var target = this.getAttribute('data-target');
@@ -22,7 +22,7 @@
       targetElement.classList.toggle('invisible');
     });
 
-    searxng.on('.media-loader', 'click', function() {
+    searxng.on('.media-loader', 'click', function () {
       var target = this.getAttribute('data-target');
       var iframe_load = d.querySelector(target + ' > iframe');
       var srctest = iframe_load.getAttribute('src');
@@ -31,8 +31,8 @@
       }
     });
 
-    searxng.selectImage = function(resultElement) {
-      /*eslint no-unused-vars: 0*/
+    searxng.selectImage = function (resultElement) {
+      /* eslint no-unused-vars: 0 */
       if (resultElement) {
         // load full size image in background
         const imgElement = resultElement.querySelector('.result-images-source img');
@@ -65,22 +65,22 @@
       searxng.scrollPageToSelected();
     }
 
-    searxng.closeDetail = function(e) {
+    searxng.closeDetail = function (e) {
       d.getElementById('results').classList.remove('image-detail-open');
       searxng.image_thumbnail_layout.align();
       searxng.scrollPageToSelected();
     }
-    searxng.on('.result-detail-close', 'click', e => { 
+    searxng.on('.result-detail-close', 'click', e => {
       e.preventDefault();
       searxng.closeDetail();
     });
     searxng.on('.result-detail-previous', 'click', e => searxng.selectPrevious(false));
     searxng.on('.result-detail-next', 'click', e => searxng.selectNext(false));
 
-    w.addEventListener('scroll', function() {
+    w.addEventListener('scroll', function () {
       var e = d.getElementById('backToTop'),
-      scrollTop = document.documentElement.scrollTop || document.body.scrollTop,
-      results = d.getElementById('results');
+        scrollTop = document.documentElement.scrollTop || document.body.scrollTop,
+        results = d.getElementById('results');
       if (e !== null) {
         if (scrollTop >= 100) {
           results.classList.add('scrolling');
diff --git a/searx/static/themes/simple/src/js/main/search.js b/searx/static/themes/simple/src/js/main/search.js
index 09a90b7e9..056eac014 100644
--- a/searx/static/themes/simple/src/js/main/search.js
+++ b/searx/static/themes/simple/src/js/main/search.js
@@ -1,48 +1,48 @@
 /* SPDX-License-Identifier: AGPL-3.0-or-later */
 /* global AutoComplete */
-(function(w, d, searxng) {
+(function (w, d, searxng) {
   'use strict';
 
   var firstFocus = true, qinput_id = "q", qinput;
 
-  function placeCursorAtEnd(element) {
+  function placeCursorAtEnd (element) {
     if (element.setSelectionRange) {
       var len = element.value.length;
       element.setSelectionRange(len, len);
     }
   }
 
-  function submitIfQuery() {
+  function submitIfQuery () {
     if (qinput.value.length  > 0) {
       var search = document.getElementById('search');
       setTimeout(search.submit.bind(search), 0);
     }
   }
 
-  function createClearButton(qinput) {
+  function createClearButton (qinput) {
     var cs = document.getElementById('clear_search');
-    var updateClearButton = function() {
+    var updateClearButton = function () {
       if (qinput.value.length === 0) {
-	cs.classList.add("empty");
+        cs.classList.add("empty");
       } else {
-	cs.classList.remove("empty");
+        cs.classList.remove("empty");
       }
     };
 
     // update status, event listener
     updateClearButton();
-    cs.addEventListener('click', function() {
-      qinput.value='';
+    cs.addEventListener('click', function () {
+      qinput.value = '';
       qinput.focus();
       updateClearButton();
     });
     qinput.addEventListener('keyup', updateClearButton, false);
   }
 
-  searxng.ready(function() {
+  searxng.ready(function () {
     qinput = d.getElementById(qinput_id);
 
-    function placeCursorAtEndOnce() {
+    function placeCursorAtEndOnce () {
       if (firstFocus) {
         placeCursorAtEnd(qinput);
         firstFocus = false;
@@ -67,7 +67,7 @@
           },
           MinChars: 4,
           Delay: 300,
-          _Position:function() {
+          _Position: function () {
             this.DOMResults.setAttribute("class", "autocomplete");
             this.DOMResults.style.top = (this.Input.offsetTop + this.Input.offsetHeight) + "px";
             this.DOMResults.style.left = this.Input.offsetLeft + "px";
@@ -76,7 +76,7 @@
         }, "#" + qinput_id);
 
         // hack, see : https://github.com/autocompletejs/autocomplete.js/issues/37
-        w.addEventListener('resize', function() {
+        w.addEventListener('resize', function () {
           var event = new CustomEvent("position");
           qinput.dispatchEvent(event);
         });
@@ -88,11 +88,11 @@
 
     // vanilla js version of search_on_category_select.js
     if (qinput !== null && d.querySelector('.help') != null && searxng.search_on_category_select) {
-      d.querySelector('.help').className='invisible';
+      d.querySelector('.help').className = 'invisible';
 
-      searxng.on('#categories input', 'change', function() {
+      searxng.on('#categories input', 'change', function () {
         var i, categories = d.querySelectorAll('#categories input[type="checkbox"]');
-        for(i=0; i<categories.length; i++) {
+        for (i = 0; i < categories.length; i++) {
           if (categories[i] !== this && categories[i].checked) {
             categories[i].click();
           }
diff --git a/searx/static/themes/simple/svg4web.svgo.js b/searx/static/themes/simple/svg4web.svgo.js
index 5b985adfe..83f74cde1 100644
--- a/searx/static/themes/simple/svg4web.svgo.js
+++ b/searx/static/themes/simple/svg4web.svgo.js
@@ -15,5 +15,5 @@ module.exports = {
     // Optimize SVG for WEB usage
     'convertStyleToAttrs',
     'removeXMLNS'
- ],
+  ],
 };