diff --git a/kallithea/public/fontello/demo.html b/kallithea/public/fontello/demo.html
--- a/kallithea/public/fontello/demo.html
+++ b/kallithea/public/fontello/demo.html
@@ -276,7 +276,7 @@ body {
     }
      </style>
     <link rel="stylesheet" href="css/animation.css"><!--[if IE 7]><link rel="stylesheet" href="css/kallithea-ie7.css"><![endif]-->
-    <script>
+    <script>'use strict';
       function toggleCodes(on) {
         var obj = document.getElementById('icons');
       
diff --git a/kallithea/public/js/codemirror_loadmode.js b/kallithea/public/js/codemirror_loadmode.js
--- a/kallithea/public/js/codemirror_loadmode.js
+++ b/kallithea/public/js/codemirror_loadmode.js
@@ -1,3 +1,5 @@
+'use strict';
+
 (function() {
   var loading = {};
   function splitCallback(cont, n) {
diff --git a/kallithea/public/js/graph.js b/kallithea/public/js/graph.js
--- a/kallithea/public/js/graph.js
+++ b/kallithea/public/js/graph.js
@@ -1,3 +1,5 @@
+'use strict';
+
 // branch_renderer.js - Rendering of branch DAGs on the client side
 //
 // Copyright 2010 Marcin Kuzminski <marcin AT python-works DOT com>
@@ -102,15 +104,15 @@ function BranchRenderer(canvas_id, conte
 			var next = document.getElementById(row_id_prefix+(idx+1));
 			var extra = 0;
 
-			cur = data[i];
-			node = cur[0];
-			in_l = cur[1];
-			closing = cur[2];
-			obsolete_node = cur[3];
-			bumped_node = cur[4];
-			divergent_node = cur[5];
-			extinct_node = cur[6];
-			unstable_node = cur[7];
+			const cur = data[i];
+			const node = cur[0];
+			const in_l = cur[1];
+			const closing = cur[2];
+			const obsolete_node = cur[3];
+			const bumped_node = cur[4];
+			const divergent_node = cur[5];
+			const extinct_node = cur[6];
+			const unstable_node = cur[7];
 
 			// center dots on the first element in a td (not necessarily the first one, but there must be one)
 			var firstincell = $(row).find('td>*:visible')[0];
@@ -119,20 +121,20 @@ function BranchRenderer(canvas_id, conte
 			var nextY = Math.floor((next == null) ? rowY + row.offsetHeight/2 : next.offsetTop + nextFirstincell.offsetTop + nextFirstincell.offsetHeight/2);
 
 			for (var j in in_l) {
-				line = in_l[j];
-				start = line[0];
-				end = line[1];
-				color = line[2];
-				obsolete_line = line[3];
+				const line = in_l[j];
+				const start = line[0];
+				const end = line[1];
+				const color = line[2];
+				const obsolete_line = line[3];
 
-				x = Math.floor(base_x - box_size * start);
+				const x = Math.floor(base_x - box_size * start);
 
 				// figure out if this is a dead-end;
 				// we want to fade away this line
 				var dead_end = true;
 				if (next != null) {
-					nextdata = data[i+1];
-					next_l = nextdata[1];
+					const nextdata = data[i+1];
+					const next_l = nextdata[1];
 					for (var k=0; k < next_l.length; ++k) {
 						if (next_l[k][0] == end) {
 							dead_end = false;
@@ -192,10 +194,10 @@ function BranchRenderer(canvas_id, conte
 				this.ctx.setLineDash([]); // reset the dashed line, if any
 			}
 
-			column = node[0];
-			color = node[1];
+			const column = node[0];
+			const color = node[1];
 
-			x = Math.floor(base_x - box_size * column);
+			const x = Math.floor(base_x - box_size * column);
 
 			this.setColor(color, 0.25, 0.75);
 			if(unstable_node)
@@ -203,7 +205,7 @@ function BranchRenderer(canvas_id, conte
 				this.ctx.fillStyle = 'rgb(255, 0, 0)';
 			}
 
-			r = this.dot_radius
+			let r = this.dot_radius
 			if (obsolete_node)
 			{
 				this.ctx.beginPath();
diff --git a/kallithea/templates/admin/admin.html b/kallithea/templates/admin/admin.html
--- a/kallithea/templates/admin/admin.html
+++ b/kallithea/templates/admin/admin.html
@@ -27,7 +27,7 @@
     </div>
 </div>
 
-<script>
+<script>'use strict';
 $(document).ready(function() {
   $('#j_filter').click(function(){
     var $jfilter = $('#j_filter');
diff --git a/kallithea/templates/admin/admin_log.html b/kallithea/templates/admin/admin_log.html
--- a/kallithea/templates/admin/admin_log.html
+++ b/kallithea/templates/admin/admin_log.html
@@ -37,7 +37,7 @@
     %endfor
 </table>
 
-<script>
+<script>'use strict';
   $(document).ready(function(){
     var $user_log = $('#user_log');
     $user_log.on('click','.pager_link',function(e){
diff --git a/kallithea/templates/admin/auth/auth_settings.html b/kallithea/templates/admin/auth/auth_settings.html
--- a/kallithea/templates/admin/auth/auth_settings.html
+++ b/kallithea/templates/admin/auth/auth_settings.html
@@ -105,7 +105,7 @@
     </div>
 </div>
 
-<script>
+<script>'use strict';
     $('.toggle-plugin').click(function(e){
         var $auth_plugins_input = $('#auth_plugins');
         var notEmpty = function(element, index, array) {
diff --git a/kallithea/templates/admin/gists/edit.html b/kallithea/templates/admin/gists/edit.html
--- a/kallithea/templates/admin/gists/edit.html
+++ b/kallithea/templates/admin/gists/edit.html
@@ -35,7 +35,7 @@
               ${(h.HTML(_('Gist was updated since you started editing. Copy your changes and click %(here)s to reload new version.'))
                              % {'here': h.link_to(_('here'),h.url('edit_gist', gist_id=c.gist.gist_access_id))})}
             </div>
-            <script>
+            <script>'use strict';
             if (typeof jQuery != 'undefined') {
                 $(".alert").alert();
             }
@@ -79,7 +79,7 @@
                 </div>
 
                 ## dynamic edit box.
-                <script>
+                <script>'use strict';
                     $(document).ready(function(){
                         var myCodeMirror = initCodeMirror(${h.js('editor_' + h.FID('f',file.path))}, ${h.jshtml(request.script_name)}, '');
 
@@ -146,7 +146,7 @@
             <a class="btn btn-default" href="${h.url('gist', gist_id=c.gist.gist_access_id)}">${_('Cancel')}</a>
             </div>
           ${h.end_form()}
-          <script>
+          <script>'use strict';
               $('#update').on('click', function(e){
                   e.preventDefault();
 
diff --git a/kallithea/templates/admin/gists/new.html b/kallithea/templates/admin/gists/new.html
--- a/kallithea/templates/admin/gists/new.html
+++ b/kallithea/templates/admin/gists/new.html
@@ -55,7 +55,7 @@
             ${h.reset('reset',_('Reset'),class_="btn btn-default btn-xs")}
             </div>
           ${h.end_form()}
-          <script>
+          <script>'use strict';
             $(document).ready(function(){
                 var myCodeMirror = initCodeMirror('editor', ${h.jshtml(request.script_name)}, '');
 
diff --git a/kallithea/templates/admin/my_account/my_account_api_keys.html b/kallithea/templates/admin/my_account/my_account_api_keys.html
--- a/kallithea/templates/admin/my_account/my_account_api_keys.html
+++ b/kallithea/templates/admin/my_account/my_account_api_keys.html
@@ -90,7 +90,7 @@ happen anyway, reset the API key on this
 ''')}</p>
 </div>
 
-<script>
+<script>'use strict';
     $(document).ready(function(){
         $("#lifetime").select2({
             'dropdownAutoWidth': true
diff --git a/kallithea/templates/admin/my_account/my_account_repos.html b/kallithea/templates/admin/my_account/my_account_repos.html
--- a/kallithea/templates/admin/my_account/my_account_repos.html
+++ b/kallithea/templates/admin/my_account/my_account_repos.html
@@ -4,7 +4,7 @@
     <table class="table" id="datatable_list_wrap" width="100%"></table>
 </div>
 
-<script>
+<script>'use strict';
   var data = ${h.js(c.data)};
   var myDataTable = $("#datatable_list_wrap").DataTable({
         data: data.records,
diff --git a/kallithea/templates/admin/my_account/my_account_watched.html b/kallithea/templates/admin/my_account/my_account_watched.html
--- a/kallithea/templates/admin/my_account/my_account_watched.html
+++ b/kallithea/templates/admin/my_account/my_account_watched.html
@@ -4,7 +4,7 @@
     <table class="table" id="datatable_list_wrap" width="100%"></table>
 </div>
 
-<script>
+<script>'use strict';
   var data = ${h.js(c.data)};
   var myDataTable = $("#datatable_list_wrap").DataTable({
         data: data.records,
diff --git a/kallithea/templates/admin/repo_groups/repo_group_add.html b/kallithea/templates/admin/repo_groups/repo_group_add.html
--- a/kallithea/templates/admin/repo_groups/repo_group_add.html
+++ b/kallithea/templates/admin/repo_groups/repo_group_add.html
@@ -61,7 +61,7 @@
     </div>
     ${h.end_form()}
 </div>
-<script>
+<script>'use strict';
     $(document).ready(function(){
         var setCopyPermsOption = function(group_val){
             if(group_val != "-1"){
diff --git a/kallithea/templates/admin/repo_groups/repo_group_edit_perms.html b/kallithea/templates/admin/repo_groups/repo_group_edit_perms.html
--- a/kallithea/templates/admin/repo_groups/repo_group_edit_perms.html
+++ b/kallithea/templates/admin/repo_groups/repo_group_edit_perms.html
@@ -102,9 +102,9 @@ ${h.form(url('edit_repo_group_perms', gr
 </div>
 ${h.end_form()}
 
-<script>
+<script>'use strict';
     function ajaxActionRevoke(obj_id, obj_type, field_id, obj_name) {
-        url = ${h.jshtml(h.url('edit_repo_group_perms_delete', group_name=c.repo_group.group_name))};
+        let url = ${h.jshtml(h.url('edit_repo_group_perms_delete', group_name=c.repo_group.group_name))};
         var revoke_msg = _TM['Confirm to revoke permission for {0}: {1} ?'].format(obj_type.replace('_', ' '), obj_name);
         if (confirm(revoke_msg)){
             var recursive = $('input[name=recursive]:checked').val();
diff --git a/kallithea/templates/admin/repo_groups/repo_group_edit_settings.html b/kallithea/templates/admin/repo_groups/repo_group_edit_settings.html
--- a/kallithea/templates/admin/repo_groups/repo_group_edit_settings.html
+++ b/kallithea/templates/admin/repo_groups/repo_group_edit_settings.html
@@ -41,7 +41,7 @@ ${h.form(url('delete_repo_group', group_
 </div>
 ${h.end_form()}
 
-<script>
+<script>'use strict';
     $(document).ready(function(){
         $("#parent_group_id").select2({
             'dropdownAutoWidth': true
diff --git a/kallithea/templates/admin/repo_groups/repo_groups.html b/kallithea/templates/admin/repo_groups/repo_groups.html
--- a/kallithea/templates/admin/repo_groups/repo_groups.html
+++ b/kallithea/templates/admin/repo_groups/repo_groups.html
@@ -30,7 +30,7 @@
         <table class="table" id="datatable_list_wrap" width="100%"></table>
     </div>
 </div>
-<script>
+<script>'use strict';
   var data = ${h.js(c.data)};
   var myDataTable = $("#datatable_list_wrap").DataTable({
         data: data.records,
diff --git a/kallithea/templates/admin/repos/repo_add_base.html b/kallithea/templates/admin/repos/repo_add_base.html
--- a/kallithea/templates/admin/repos/repo_add_base.html
+++ b/kallithea/templates/admin/repos/repo_add_base.html
@@ -65,7 +65,7 @@ ${h.form(url('repos'))}
             </div>
         </div>
 </div>
-<script>
+<script>'use strict';
     $(document).ready(function(){
         var setCopyPermsOption = function(group_val){
             if(group_val != "-1"){
diff --git a/kallithea/templates/admin/repos/repo_creating.html b/kallithea/templates/admin/repos/repo_creating.html
--- a/kallithea/templates/admin/repos/repo_creating.html
+++ b/kallithea/templates/admin/repos/repo_creating.html
@@ -42,7 +42,7 @@
     </div>
 </div>
 
-<script>
+<script>'use strict';
 (function worker() {
   $.ajax({
     url: ${h.js(h.url('repo_check_home', repo_name=c.repo_name, repo=c.repo, task_id=c.task_id))},
diff --git a/kallithea/templates/admin/repos/repo_edit_advanced.html b/kallithea/templates/admin/repos/repo_edit_advanced.html
--- a/kallithea/templates/admin/repos/repo_edit_advanced.html
+++ b/kallithea/templates/admin/repos/repo_edit_advanced.html
@@ -9,7 +9,7 @@ ${h.form(url('edit_repo_advanced_fork', 
 </div>
 ${h.end_form()}
 
-<script>
+<script>'use strict';
     $(document).ready(function(){
         $("#id_fork_of").select2({
             'dropdownAutoWidth': true
diff --git a/kallithea/templates/admin/repos/repo_edit_permissions.html b/kallithea/templates/admin/repos/repo_edit_permissions.html
--- a/kallithea/templates/admin/repos/repo_edit_permissions.html
+++ b/kallithea/templates/admin/repos/repo_edit_permissions.html
@@ -87,9 +87,9 @@ ${h.form(url('edit_repo_perms_update', r
 </div>
 ${h.end_form()}
 
-<script>
+<script>'use strict';
     function ajaxActionRevoke(obj_id, obj_type, field_id, obj_name) {
-        url = ${h.js(h.url('edit_repo_perms_revoke',repo_name=c.repo_name))};
+        let url = ${h.js(h.url('edit_repo_perms_revoke',repo_name=c.repo_name))};
         var revoke_msg = _TM['Confirm to revoke permission for {0}: {1} ?'].format(obj_type.replace('_', ' '), obj_name);
         if (confirm(revoke_msg)){
             ajaxActionRevokePermission(url, obj_id, obj_type, field_id);
diff --git a/kallithea/templates/admin/repos/repo_edit_settings.html b/kallithea/templates/admin/repos/repo_edit_settings.html
--- a/kallithea/templates/admin/repos/repo_edit_settings.html
+++ b/kallithea/templates/admin/repos/repo_edit_settings.html
@@ -103,7 +103,7 @@ ${h.form(url('update_repo', repo_name=c.
     </div>
     ${h.end_form()}
 
-<script>
+<script>'use strict';
     $(document).ready(function(){
         $('#repo_landing_rev').select2({
             'dropdownAutoWidth': true
diff --git a/kallithea/templates/admin/repos/repos.html b/kallithea/templates/admin/repos/repos.html
--- a/kallithea/templates/admin/repos/repos.html
+++ b/kallithea/templates/admin/repos/repos.html
@@ -29,7 +29,7 @@
     </div>
 
 </div>
-<script>
+<script>'use strict';
   var data = ${h.js(c.data)};
   var myDataTable = $("#datatable_list_wrap").DataTable({
         data: data.records,
diff --git a/kallithea/templates/admin/settings/settings_hooks.html b/kallithea/templates/admin/settings/settings_hooks.html
--- a/kallithea/templates/admin/settings/settings_hooks.html
+++ b/kallithea/templates/admin/settings/settings_hooks.html
@@ -50,7 +50,7 @@ ${h.form(url('admin_settings_hooks'), me
 ${h.end_form()}
 % endif
 
-<script>
+<script>'use strict';
 function delete_hook(hook_id, field_id) {
     var sUrl = ${h.js(h.url('admin_settings_hooks_delete'))};
     var success = function (o) {
diff --git a/kallithea/templates/admin/settings/settings_vcs.html b/kallithea/templates/admin/settings/settings_vcs.html
--- a/kallithea/templates/admin/settings/settings_vcs.html
+++ b/kallithea/templates/admin/settings/settings_vcs.html
@@ -69,7 +69,7 @@ ${h.form(url('admin_settings'), method='
     </div>
     ${h.end_form()}
 
-    <script>
+    <script>'use strict';
         $(document).ready(function(){
             $('#path_unlock').on('click', function(e){
                 $('#path_unlock_icon').removeClass('icon-lock');
diff --git a/kallithea/templates/admin/user_groups/user_group_add.html b/kallithea/templates/admin/user_groups/user_group_add.html
--- a/kallithea/templates/admin/user_groups/user_group_add.html
+++ b/kallithea/templates/admin/user_groups/user_group_add.html
@@ -52,7 +52,7 @@
     ${h.end_form()}
 </div>
 
-<script>
+<script>'use strict';
     $(document).ready(function(){
         $('#users_group_name').focus();
     });
diff --git a/kallithea/templates/admin/user_groups/user_group_edit_perms.html b/kallithea/templates/admin/user_groups/user_group_edit_perms.html
--- a/kallithea/templates/admin/user_groups/user_group_edit_perms.html
+++ b/kallithea/templates/admin/user_groups/user_group_edit_perms.html
@@ -92,9 +92,9 @@ ${h.form(url('edit_user_group_perms_upda
 </div>
 ${h.end_form()}
 
-<script>
+<script>'use strict';
     function ajaxActionRevoke(obj_id, obj_type, field_id, obj_name) {
-        url = ${h.js(h.url('edit_user_group_perms_delete', id=c.user_group.users_group_id))};
+        let url = ${h.js(h.url('edit_user_group_perms_delete', id=c.user_group.users_group_id))};
         var revoke_msg = _TM['Confirm to revoke permission for {0}: {1} ?'].format(obj_type.replace('_', ' '), obj_name);
         if (confirm(revoke_msg)){
             ajaxActionRevokePermission(url, obj_id, obj_type, field_id);
diff --git a/kallithea/templates/admin/user_groups/user_group_edit_settings.html b/kallithea/templates/admin/user_groups/user_group_edit_settings.html
--- a/kallithea/templates/admin/user_groups/user_group_edit_settings.html
+++ b/kallithea/templates/admin/user_groups/user_group_edit_settings.html
@@ -48,6 +48,6 @@ ${h.form(url('update_users_group', id=c.
                 </div>
     </div>
 ${h.end_form()}
-<script>
+<script>'use strict';
   MultiSelectWidget('users_group_members','available_members','edit_users_group');
 </script>
diff --git a/kallithea/templates/admin/user_groups/user_groups.html b/kallithea/templates/admin/user_groups/user_groups.html
--- a/kallithea/templates/admin/user_groups/user_groups.html
+++ b/kallithea/templates/admin/user_groups/user_groups.html
@@ -29,7 +29,7 @@
         <table class="table" id="datatable_list_wrap" width="100%"></table>
     </div>
 </div>
-<script>
+<script>'use strict';
     var data = ${h.js(c.data)};
     var $dataTable = $("#datatable_list_wrap").DataTable({
         data: data.records,
diff --git a/kallithea/templates/admin/users/user_add.html b/kallithea/templates/admin/users/user_add.html
--- a/kallithea/templates/admin/users/user_add.html
+++ b/kallithea/templates/admin/users/user_add.html
@@ -84,7 +84,7 @@
     ${h.end_form()}
 </div>
 
-<script>
+<script>'use strict';
     $(document).ready(function(){
         $('#username').focus();
     });
diff --git a/kallithea/templates/admin/users/user_edit_api_keys.html b/kallithea/templates/admin/users/user_edit_api_keys.html
--- a/kallithea/templates/admin/users/user_edit_api_keys.html
+++ b/kallithea/templates/admin/users/user_edit_api_keys.html
@@ -77,7 +77,7 @@
     ${h.end_form()}
 </div>
 
-<script>
+<script>'use strict';
     $(document).ready(function(){
         $("#lifetime").select2({
             'dropdownAutoWidth': true
diff --git a/kallithea/templates/admin/users/users.html b/kallithea/templates/admin/users/users.html
--- a/kallithea/templates/admin/users/users.html
+++ b/kallithea/templates/admin/users/users.html
@@ -28,7 +28,7 @@
     </div>
 </div>
 
-<script>
+<script>'use strict';
     var data = ${h.js(c.data)};
     var $dataTable = $("#datatable_list_wrap").DataTable({
         data: data.records,
diff --git a/kallithea/templates/base/base.html b/kallithea/templates/base/base.html
--- a/kallithea/templates/base/base.html
+++ b/kallithea/templates/base/base.html
@@ -177,7 +177,7 @@
     </div>
     </div>
   </nav>
-  <script>
+  <script>'use strict';
     $(document).ready(function() {
       var bcache = {};
 
@@ -399,7 +399,7 @@
     </li>
   </ul>
 
-    <script>
+    <script>'use strict';
         $(document).ready(function(){
             var visual_show_public_icon = ${h.js(c.visual.show_public_icon)};
             var cache = {}
@@ -527,7 +527,7 @@
         </div>
     </div>
 
-    <script>
+    <script>'use strict';
       $(document).ready(function(){
           activate_parent_child_links();
       });
diff --git a/kallithea/templates/base/flash_msg.html b/kallithea/templates/base/flash_msg.html
--- a/kallithea/templates/base/flash_msg.html
+++ b/kallithea/templates/base/flash_msg.html
@@ -9,7 +9,7 @@
             </div>
         % endfor
     % endif
-    <script>
+    <script>'use strict';
     if (typeof jQuery != 'undefined') {
         $(".alert").alert();
     }
diff --git a/kallithea/templates/base/perms_summary.html b/kallithea/templates/base/perms_summary.html
--- a/kallithea/templates/base/perms_summary.html
+++ b/kallithea/templates/base/perms_summary.html
@@ -97,7 +97,7 @@
         %endif
      %endfor
 </div>
-<script>
+<script>'use strict';
     $(document).ready(function(){
         var show_empty = function(section){
             var visible = $('.section_{0} tr.perm_row:visible'.format(section)).length;
diff --git a/kallithea/templates/base/root.html b/kallithea/templates/base/root.html
--- a/kallithea/templates/base/root.html
+++ b/kallithea/templates/base/root.html
@@ -21,7 +21,7 @@
         <%block name="css_extra"/>
 
         ## JAVASCRIPT ##
-        <script>
+        <script>'use strict';
             ## JS translations map
             var TRANSLATION_MAP = {
                 'Cancel': ${h.jshtml(_("Cancel"))},
@@ -77,7 +77,7 @@
         <script src="${h.url('/js/base.js', ver=c.kallithea_version)}"></script>
         ## EXTRA FOR JS
         <%block name="js_extra"/>
-        <script>
+        <script>'use strict';
             $(document).ready(function(){
               tooltip_activate();
               show_more_event();
diff --git a/kallithea/templates/changelog/changelog.html b/kallithea/templates/changelog/changelog.html
--- a/kallithea/templates/changelog/changelog.html
+++ b/kallithea/templates/changelog/changelog.html
@@ -81,7 +81,7 @@ ${self.repo_context_bar('changelog', c.f
                 ${c.cs_pagination.pager()}
 
         <script src="${h.url('/js/graph.js', ver=c.kallithea_version)}"></script>
-        <script>
+        <script>'use strict';
             var jsdata = ${h.js(c.jsdata)};
             var graph = new BranchRenderer('graph_canvas', 'graph_content', 'chg_');
 
diff --git a/kallithea/templates/changelog/changelog_table.html b/kallithea/templates/changelog/changelog_table.html
--- a/kallithea/templates/changelog/changelog_table.html
+++ b/kallithea/templates/changelog/changelog_table.html
@@ -110,7 +110,7 @@
     </tbody>
     </table>
 
-<script>
+<script>'use strict';
   $(document).ready(function() {
     $('#changesets .expand_commit').on('click',function(e){
       $(this).next('.mid').find('.message > div').toggleClass('hidden');
diff --git a/kallithea/templates/changeset/changeset.html b/kallithea/templates/changeset/changeset.html
--- a/kallithea/templates/changeset/changeset.html
+++ b/kallithea/templates/changeset/changeset.html
@@ -22,7 +22,7 @@ ${self.repo_context_bar('changelog', c.c
   <div class="panel-heading clearfix">
     ${self.breadcrumbs()}
   </div>
-  <script>
+  <script>'use strict';
     AJAX_COMMENT_URL = ${h.js(url('changeset_comment',repo_name=c.repo_name,revision=c.changeset.raw_id))};
     AJAX_COMMENT_DELETE_URL = ${h.js(url('changeset_comment_delete',repo_name=c.repo_name,comment_id='__COMMENT_ID__'))};
   </script>
@@ -184,7 +184,7 @@ ${self.repo_context_bar('changelog', c.c
     </div>
 
     ## FORM FOR MAKING JS ACTION AS CHANGESET COMMENTS
-    <script>
+    <script>'use strict';
       $(document).ready(function(){
           $('.code-difftable').on('click', '.add-bubble', function(e){
               show_comment_form($(this));
diff --git a/kallithea/templates/changeset/changeset_file_comment.html b/kallithea/templates/changeset/changeset_file_comment.html
--- a/kallithea/templates/changeset/changeset_file_comment.html
+++ b/kallithea/templates/changeset/changeset_file_comment.html
@@ -192,7 +192,7 @@
   </div>
 </div>
 
-<script>
+<script>'use strict';
 
 $(document).ready(function () {
 
diff --git a/kallithea/templates/changeset/diff_block.html b/kallithea/templates/changeset/diff_block.html
--- a/kallithea/templates/changeset/diff_block.html
+++ b/kallithea/templates/changeset/diff_block.html
@@ -96,7 +96,7 @@
 </%def>
 
 <%def name="diff_block_js()">
-<script>
+<script>'use strict';
 $(document).ready(function(){
     $('.btn-image-diff-show').click(function(e){
         $('.btn-image-diff-show').hide();
diff --git a/kallithea/templates/compare/compare_cs.html b/kallithea/templates/compare/compare_cs.html
--- a/kallithea/templates/compare/compare_cs.html
+++ b/kallithea/templates/compare/compare_cs.html
@@ -66,7 +66,7 @@
 <script src="${h.url('/js/graph.js', ver=c.kallithea_version)}"></script>
 %endif
 
-<script>
+<script>'use strict';
     var jsdata = ${h.js(c.jsdata)};
     var graph = new BranchRenderer('graph_canvas', 'graph_content_pr', 'chg_');
 
diff --git a/kallithea/templates/compare/compare_diff.html b/kallithea/templates/compare/compare_diff.html
--- a/kallithea/templates/compare/compare_diff.html
+++ b/kallithea/templates/compare/compare_diff.html
@@ -98,7 +98,7 @@ ${self.repo_context_bar('changelog')}
     </div>
 
 </div>
-    <script>
+    <script>'use strict';
 
    $(document).ready(function(){
     var cache = {};
diff --git a/kallithea/templates/files/diff_2way.html b/kallithea/templates/files/diff_2way.html
--- a/kallithea/templates/files/diff_2way.html
+++ b/kallithea/templates/files/diff_2way.html
@@ -60,7 +60,7 @@ ${self.repo_context_bar('changelog')}
         </div>
     </div>
 
-<script>
+<script>'use strict';
 var orig1_url = ${h.jshtml(h.url('files_raw_home',repo_name=c.repo_name,f_path=c.node1.path,revision=c.cs1.raw_id))};
 var orig2_url = ${h.jshtml(h.url('files_raw_home',repo_name=c.repo_name,f_path=c.node2.path,revision=c.cs2.raw_id))};
 
diff --git a/kallithea/templates/files/files.html b/kallithea/templates/files/files.html
--- a/kallithea/templates/files/files.html
+++ b/kallithea/templates/files/files.html
@@ -36,7 +36,7 @@ ${self.repo_context_bar('files', c.revis
     </div>
 </div>
 
-<script>
+<script>'use strict';
 var CACHE = {};
 var CACHE_EXPIRE = 5*60*1000; //cache for 5*60s
 //used to construct links from the search list
@@ -125,16 +125,16 @@ var post_load_state = function(state) {
     }
 
     function highlight_lines(lines){
-        for(pos in lines){
+        for(let pos in lines){
           $('#L'+lines[pos]).css('background-color','#FFFFBE');
         }
     }
-    page_highlights = location.href.substring(location.href.indexOf('#')+1).split('L');
+    let page_highlights = location.href.substring(location.href.indexOf('#')+1).split('L');
     if (page_highlights.length == 2){
-       highlight_ranges  = page_highlights[1].split(",");
+       let highlight_ranges  = page_highlights[1].split(",");
 
        var h_lines = [];
-       for (pos in highlight_ranges){
+       for (let pos in highlight_ranges){
             var _range = highlight_ranges[pos].split('-');
             if(_range.length == 2){
                 var start = parseInt(_range[0]);
diff --git a/kallithea/templates/files/files_add.html b/kallithea/templates/files/files_add.html
--- a/kallithea/templates/files/files_add.html
+++ b/kallithea/templates/files/files_add.html
@@ -70,7 +70,7 @@ ${self.repo_context_bar('files')}
               </div>
             </div>
             ${h.end_form()}
-            <script>
+            <script>'use strict';
                 $(document).ready(function(){
                     var reset_url = ${h.jshtml(h.url('files_home',repo_name=c.repo_name,revision=c.cs.raw_id,f_path=c.f_path))};
                     var myCodeMirror = initCodeMirror('editor', ${h.jshtml(request.script_name)}, reset_url);
diff --git a/kallithea/templates/files/files_browser.html b/kallithea/templates/files/files_browser.html
--- a/kallithea/templates/files/files_browser.html
+++ b/kallithea/templates/files/files_browser.html
@@ -109,7 +109,7 @@
     </div>
 </div>
 
-<script>
+<script>'use strict';
     $(document).ready(function(){
         // init node filter if we pass GET param ?search=1
         var search_GET = ${h.js(request.GET.get('search',''))};
diff --git a/kallithea/templates/files/files_edit.html b/kallithea/templates/files/files_edit.html
--- a/kallithea/templates/files/files_edit.html
+++ b/kallithea/templates/files/files_edit.html
@@ -77,7 +77,7 @@ ${self.repo_context_bar('files')}
     </div>
 </div>
 
-<script>
+<script>'use strict';
     $(document).ready(function(){
         var reset_url = ${h.jshtml(h.url('files_home',repo_name=c.repo_name,revision=c.cs.raw_id,f_path=c.file.path))};
         var myCodeMirror = initCodeMirror('editor', ${h.jshtml(request.script_name)}, reset_url);
diff --git a/kallithea/templates/followers/followers.html b/kallithea/templates/followers/followers.html
--- a/kallithea/templates/followers/followers.html
+++ b/kallithea/templates/followers/followers.html
@@ -25,7 +25,7 @@ ${self.repo_context_bar('followers')}
         </div>
     </div>
 </div>
-<script>
+<script>'use strict';
   $(document).ready(function(){
     var $followers = $('#followers');
     $followers.on('click','.pager_link',function(e){
diff --git a/kallithea/templates/forks/fork.html b/kallithea/templates/forks/fork.html
--- a/kallithea/templates/forks/fork.html
+++ b/kallithea/templates/forks/fork.html
@@ -88,7 +88,7 @@ ${self.repo_context_bar('createfork')}
     </div>
     ${h.end_form()}
 </div>
-<script>
+<script>'use strict';
     $(document).ready(function(){
         $("#repo_group").select2({
             'dropdownAutoWidth': true
diff --git a/kallithea/templates/forks/forks.html b/kallithea/templates/forks/forks.html
--- a/kallithea/templates/forks/forks.html
+++ b/kallithea/templates/forks/forks.html
@@ -25,7 +25,7 @@ ${self.repo_context_bar('showforks')}
         </div>
     </div>
 </div>
-<script>
+<script>'use strict';
   $(document).ready(function(){
       var $forks = $('#forks');
       $forks.on('click','.pager_link',function(e){
diff --git a/kallithea/templates/index_base.html b/kallithea/templates/index_base.html
--- a/kallithea/templates/index_base.html
+++ b/kallithea/templates/index_base.html
@@ -44,7 +44,7 @@
         </div>
     </div>
 
-      <script>
+      <script>'use strict';
         var data = ${h.js(c.data)},
             $dataTable = $("#repos_list_wrap").DataTable({
                 data: data.records,
diff --git a/kallithea/templates/journal/journal.html b/kallithea/templates/journal/journal.html
--- a/kallithea/templates/journal/journal.html
+++ b/kallithea/templates/journal/journal.html
@@ -41,7 +41,7 @@
         </div>
     </div>
 
-<script>
+<script>'use strict';
 
     $('#j_filter').click(function(){
         var $jfilter = $('#j_filter');
@@ -72,7 +72,7 @@
 
 </script>
 
-<script>
+<script>'use strict';
     $(document).ready(function(){
         var $journal = $('#journal');
         $journal.on('click','.pager_link',function(e){
diff --git a/kallithea/templates/login.html b/kallithea/templates/login.html
--- a/kallithea/templates/login.html
+++ b/kallithea/templates/login.html
@@ -64,7 +64,7 @@
             </div>
         </div>
         ${h.end_form()}
-        <script>
+        <script>'use strict';
         $(document).ready(function(){
             $('#username').focus();
         });
diff --git a/kallithea/templates/password_reset.html b/kallithea/templates/password_reset.html
--- a/kallithea/templates/password_reset.html
+++ b/kallithea/templates/password_reset.html
@@ -53,7 +53,7 @@
                 </div>
         </div>
         ${h.end_form()}
-        <script>
+        <script>'use strict';
          $(document).ready(function(){
             $('#email').focus();
          });
diff --git a/kallithea/templates/pullrequests/pullrequest.html b/kallithea/templates/pullrequests/pullrequest.html
--- a/kallithea/templates/pullrequests/pullrequest.html
+++ b/kallithea/templates/pullrequests/pullrequest.html
@@ -92,7 +92,7 @@ ${self.repo_context_bar('showpullrequest
 </div>
 
 <script src="${h.url('/js/graph.js', ver=c.kallithea_version)}"></script>
-<script>
+<script>'use strict';
   pyroutes.register('pullrequest_repo_info', ${h.js(url('pullrequest_repo_info',repo_name='%(repo_name)s'))}, ['repo_name']);
 
   var pendingajax = undefined;
@@ -162,7 +162,7 @@ ${self.repo_context_bar('showpullrequest
           '__other_ref_name__': other_ref[2]
       }; // gather the org/other ref and repo here
 
-      for (k in rev_data){
+      for (let k in rev_data){
           url = url.replace(k,rev_data[k]);
       }
 
diff --git a/kallithea/templates/pullrequests/pullrequest_show.html b/kallithea/templates/pullrequests/pullrequest_show.html
--- a/kallithea/templates/pullrequests/pullrequest_show.html
+++ b/kallithea/templates/pullrequests/pullrequest_show.html
@@ -312,7 +312,7 @@ ${self.repo_context_bar('showpullrequest
             </div>
         </div>
     </div>
-    <script>
+    <script>'use strict';
     // TODO: switch this to pyroutes
     AJAX_COMMENT_URL = ${h.js(url('pullrequest_comment',repo_name=c.repo_name,pull_request_id=c.pull_request.pull_request_id))};
     AJAX_COMMENT_DELETE_URL = ${h.js(url('pullrequest_comment_delete',repo_name=c.repo_name,comment_id='__COMMENT_ID__'))};
@@ -343,7 +343,7 @@ ${self.repo_context_bar('showpullrequest
     ## main comment form and it status
     ${comment.comments(change_status=c.allowed_to_change_status)}
 
-    <script>
+    <script>'use strict';
       $(document).ready(function(){
           PullRequestAutoComplete($('#user'));
           SimpleUserAutoComplete($('#owner'));
diff --git a/kallithea/templates/register.html b/kallithea/templates/register.html
--- a/kallithea/templates/register.html
+++ b/kallithea/templates/register.html
@@ -90,7 +90,7 @@
                 </div>
         </div>
         ${h.end_form()}
-        <script>
+        <script>'use strict';
         $(document).ready(function(){
             $('#username').focus();
         });
diff --git a/kallithea/templates/summary/statistics.html b/kallithea/templates/summary/statistics.html
--- a/kallithea/templates/summary/statistics.html
+++ b/kallithea/templates/summary/statistics.html
@@ -51,7 +51,7 @@ ${self.repo_context_bar('summary')}
     </div>
 </div>
 
-<script>
+<script>'use strict';
 var data = ${h.js(c.trending_languages)};
 var total = 0;
 var tbl = document.createElement('table');
@@ -103,7 +103,7 @@ for (var i=0;i<data.length;i++){
     if(cnt == 3){
         var show_more = document.createElement('tr');
         var td = document.createElement('td');
-        lnk = document.createElement('a');
+        let lnk = document.createElement('a');
 
         lnk.href='#';
         lnk.innerHTML = ${h.jshtml(_('Show more'))};
@@ -118,7 +118,7 @@ for (var i=0;i<data.length;i++){
 }
 
 </script>
-<script>
+<script>'use strict';
 
 /**
  * Plots summary graph
@@ -260,7 +260,7 @@ function SummaryPlot(from,to,dataset,ove
         for(var key in dataset){
 
             for(var ds in dataset[key].data){
-                commit_data = dataset[key].data[ds];
+                let commit_data = dataset[key].data[ds];
                 if (commit_data.time >= ranges.xaxis.from && commit_data.time <= ranges.xaxis.to){
                     if(new_dataset[key] === undefined){
                         new_dataset[key] = {data:[],label:key};
@@ -288,7 +288,7 @@ function SummaryPlot(from,to,dataset,ove
     * redraw using new checkbox data
     */
     function plotchoiced(e){
-        args = e.data;
+        let args = e.data;
         var cur_data = args[0];
         var cur_ranges = args[1];
 
diff --git a/kallithea/templates/summary/summary.html b/kallithea/templates/summary/summary.html
--- a/kallithea/templates/summary/summary.html
+++ b/kallithea/templates/summary/summary.html
@@ -27,7 +27,7 @@
   <link href="${h.url('atom_feed_home',repo_name=c.db_repo.repo_name,api_key=request.authuser.api_key)}" rel="alternate" title="${_('%s ATOM feed') % c.repo_name}" type="application/atom+xml" />
   <link href="${h.url('rss_feed_home',repo_name=c.db_repo.repo_name,api_key=request.authuser.api_key)}" rel="alternate" title="${_('%s RSS feed') % c.repo_name}" type="application/rss+xml" />
 
-  <script>
+  <script>'use strict';
   redirect_hash_branch = function(){
     var branch = window.location.hash.replace(/^#(.*)/, '$1');
     if (branch){
@@ -238,7 +238,7 @@ hg push ${c.clone_repo_url}
 </div>
 %endif
 
-<script>
+<script>'use strict';
 $(document).ready(function(){
     $('#clone-url input').click(function(e){
         if($(this).hasClass('selected')){
@@ -309,7 +309,7 @@ $(document).ready(function(){
     $('#download_options').change(function(e){
        var new_cs = e.added
 
-       for(k in tmpl_links){
+       for(let k in tmpl_links){
            var s = $('#'+k+'_link');
            if(s){
              var title_tmpl = ${h.jshtml(_('Download %s as %s') % ('__CS_NAME__','__CS_EXT__'))};
@@ -334,7 +334,7 @@ $(document).ready(function(){
 </script>
 
 %if c.show_stats:
-<script>
+<script>'use strict';
 $(document).ready(function(){
     var data = ${h.js(c.trending_languages)};
     var total = 0;
@@ -393,7 +393,7 @@ $(document).ready(function(){
         if(cnt == 3){
             var show_more = document.createElement('tr');
             var td = document.createElement('td');
-            lnk = document.createElement('a');
+            let lnk = document.createElement('a');
 
             lnk.href='#';
             lnk.innerHTML = ${h.jshtml(_('Show more'))};