diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 2ca5bb3..09fb26e 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -67,3 +67,7 @@ repos:
             tests|
             scripts
           )
+  - repo: https://github.com/pre-commit/mirrors-eslint
+    rev: 'v8.53.0'
+    hooks:
+      - id: eslint
diff --git a/rctab/static/scripts/download_table.js b/rctab/static/scripts/download_table.js
index 36e90ad..49e5671 100644
--- a/rctab/static/scripts/download_table.js
+++ b/rctab/static/scripts/download_table.js
@@ -1,17 +1,18 @@
-/*ToDo*/
-function download_table_as_csv(table_id, start_date, separator = ',') {
+"use strict";
+
+function downloadTableAsCsv(table_id, start_date, separator = ',') {
     // see https://stackoverflow.com/questions/15547198/export-html-table-to-csv-using-vanilla-javascript
     // Select rows from table_id
-    var rows = document.querySelectorAll('table#' + table_id + ' tr');
-    var fulltable = document.getElementById("fullusagetable")
+    let rows = document.querySelectorAll('table#' + table_id + ' tr');
+    let fulltable = document.getElementById("fullusagetable")
     fulltable.style.display = "block"
     // Construct csv
-    var csv = [];
-    for (var i = 0; i < rows.length; i++) {
-        var row = [], cols = rows[i].querySelectorAll('td, th');
-        for (var j = 0; j < cols.length; j++) {
+    let csv = [];
+    for (let i = 0; i < rows.length; i++) {
+        let row = [], cols = rows[i].querySelectorAll('td, th');
+        for (let j = 0; j < cols.length; j++) {
             // Clean innertext to remove multiple spaces and jumpline (break csv)
-            var data = cols[j].innerText.replace(/(\r\n|\n|\r)/gm, '').replace(/(\s\s)/gm, ' ')
+            let data = cols[j].innerText.replace(/(\r\n|\n|\r)/gm, '').replace(/(\s\s)/gm, ' ')
             // Escape double-quote with double-double-quote
             data = data.replace(/"/g, '""');
             // Push escaped string
@@ -19,10 +20,10 @@ function download_table_as_csv(table_id, start_date, separator = ',') {
         }
         csv.push(row.join(separator));
     }
-    var csv_string = csv.join('\n');
+    let csv_string = csv.join('\n');
     // Download it
-    var filename = table_id + '_' + new Date().toLocaleDateString().replace(/\//g, '-') + '_' + start_date + '.csv';
-    var link = document.createElement('a');
+    let filename = table_id + '_' + new Date().toLocaleDateString().replace(/\//g, '-') + '_' + start_date + '.csv';
+    let link = document.createElement('a');
     link.style.display = 'none';
     link.setAttribute('target', '_blank');
     link.setAttribute('href', 'data:text/csv;charset=utf-8,' + encodeURIComponent(csv_string));
diff --git a/rctab/static/scripts/tab_functions.js b/rctab/static/scripts/tab_functions.js
index 549d433..bf8687e 100644
--- a/rctab/static/scripts/tab_functions.js
+++ b/rctab/static/scripts/tab_functions.js
@@ -1,21 +1,20 @@
+"use strict";
+
 /*ToDo*/
 function openTab(evt, tabName) {
     // Show the selected tab (tabName). Set the selected tab to be the active
     // tab. The the selected tab will then be activated on page refresh.
     sessionStorage.setItem('currentTab', tabName + "_btn")
 
-    // Declare all variables
-    var i, tabcontent, tablinks;
-
     // Get all elements with class="tabcontent" and hide them
-    tabcontent = document.getElementsByClassName("tabcontent");
-    for (i = 0; i < tabcontent.length; i++) {
+    let tabcontent = document.getElementsByClassName("tabcontent");
+    for (let i = 0; i < tabcontent.length; i++) {
         tabcontent[i].style.display = "none";
     }
 
     // Get all elements with class="tablinks" and remove the class "active"
-    tablinks = document.getElementsByClassName("tablinks");
-    for (i = 0; i < tablinks.length; i++) {
+    let tablinks = document.getElementsByClassName("tablinks");
+    for (let i = 0; i < tablinks.length; i++) {
         tablinks[i].className = tablinks[i].className.replace(" active", "");
     }
 
diff --git a/rctab/static/scripts/tables.js b/rctab/static/scripts/tables.js
index 655a7ef..3599d3b 100644
--- a/rctab/static/scripts/tables.js
+++ b/rctab/static/scripts/tables.js
@@ -1,19 +1,4 @@
-/*ToDo*/
-$(document).ready( function () {
-    // Only run on the main page
-    if ($('#subscription_table_all').length > 0) {
-        $('#subscription_table_all').DataTable({
-            columnDefs: [
-                { orderable: false, targets: 0 }
-            ],
-            order: [[2, 'asc']],
-            paging: false,
-        });
-        // Hide abolished rows by default
-        hideAbolishedRows(true);
-        document.getElementById("show_abolished_checkbox").checked = false;
-    }
-} );
+"use strict";
 
 function hideAbolishedRows(input) {
   // Hide or show abolished rows by finding rows with the red x and turning
@@ -31,3 +16,19 @@ function hideAbolishedRows(input) {
       }
   })
 }
+
+$(document).ready( function () {
+    // Only run on the main page
+    if ($('#subscription_table_all').length > 0) {
+        $('#subscription_table_all').DataTable({
+            columnDefs: [
+                { orderable: false, targets: 0 }
+            ],
+            order: [[2, 'asc']],
+            paging: false,
+        });
+        // Hide abolished rows by default
+        hideAbolishedRows(true);
+        document.getElementById("show_abolished_checkbox").checked = false;
+    }
+} );
diff --git a/rctab/templates/azure_usage_info.html b/rctab/templates/azure_usage_info.html
index a4f52fa..aa8f6ed 100644
--- a/rctab/templates/azure_usage_info.html
+++ b/rctab/templates/azure_usage_info.html
@@ -3,7 +3,7 @@
 {% else %}
 <div>
     <h3>Subscription usage since {{ time_frame_start }}</h3>
-    <button id="download_btn" class="download" onclick="download_table_as_csv('subscription_usage', '{{ time_frame_start }}');">Download full usage data as CSV</button>
+    <button id="download_btn" class="download" onclick="downloadTableAsCsv('subscription_usage', '{{ time_frame_start }}');">Download full usage data as CSV</button>
 </div>
     <div class="col usageFigure">
         {{ usage_fig | safe }}