Hi Embeno, JavaScript is enabled by default. If lots of sites tell you it is not enabled, there is a setting you can check, but if it's only a few sites, there might be another reason they are telling you this: a Firefox setting or an add-on is blocking something from running in the page, or the page doesn't work in Firefox. Here are some things you can check: '''''Content Blocking Add-ons''''' Extensions such as Adblock Plus, Blur, Disconnect, DuckDuckGo Privacy Essentials, Ghostery, NoScript, Privacy Badger, and uBlock Origin may block ad scripts, tracking scripts, and other elements of a site. Usually you can find a toolbar button for each add-on to manage blocked content in a page. There may or may not be a number on the icon indicating the number of blocked items; you sometimes need to click the button to see what's going on and test whether you need to make an exception for this site. '''''Firefox's Enhanced Tracking Protection Feature''''' You can use the shield icon at the left end of the address bar to check whether Firefox is blocking content in the page -- usually that content is a script from a known tracking server, but you can make an exception to test out whether this is the problem. Find more information in the following article: [[Enhanced Tracking Protection in Firefox for desktop]] '''''Master Setting for JavaScript''''' (1) In a new tab, type or paste '''about:config''' in the address bar and press Enter/Return. Click the button accepting the risk. ''More info on about:config:'' [[Configuration Editor for Firefox]]. ''The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.'' (2) In the search box in the page, type or paste '''javascript.enabled''' and pause while the list is filtered (3) If the preference is bolded and has a value of false, double-click it (or click the Toggle button or Reset button at the right end of the row) to restore the default value of true