As you all might know, Mozilla is migrating its addon system to WebExtension and so many addons break from version 57+, see more here:


In the past I used "Yes Script" and "No Script" to allow Javascript everywhere and block it on specific sites only. However they are not supported in FF 57 (I'm on beta now) and the developer of "Yes Script" does not plan to upgrade it in the future. But I'd like to block JS on specific sites. Any idea how I might achieve that?

Could I do that modifying prefs.js or user.js? I would prefer to do this without any extension if possible. Thanks.

  • 1
    Someone suggested uMatrix – Nemo Nov 19 '17 at 6:34
  • You may use WaterFox with legacy support. – neverMind9 Aug 22 '18 at 16:23

Solved it by developing an extension myself: https://addons.mozilla.org/en-US/firefox/addon/yesscript2/

  • I've reached version 4.0 where Sync works fine and I've changed functionality: There are 3 states from now on instead of the original 2 ones: 1) no blocking (grey icon), 2) half blocking (internal script are enabled while externals are blocked, blue icon), 3) full blocking (internal and external scripts are blocked too, red icon) – log69 Nov 29 '17 at 13:03
  • The hero we don't deserve! – frandroid Sep 25 '19 at 13:10
  • Is there a reason this cannot work on older versions of FireFox? I have an older computer, and was hoping to be able to use an add-on this simple on it... – Alex Jan 6 '20 at 16:14

uBlock Origin in "advanced mode" can block scripts with so-called dynamic filtering rules. It also distinguishes scripts between inline, 1st party and 3rd party. You can set up a default policy of blocking for all sites and selectively override it for specific sites.

uMatrix is even better and allows more fine-grained control


It isn't possible to disable JavaScript per domain without an add-on.

NoScript version 10 has been released, it supports Firefox 57.

Or you may want to try uMatrix as a replacement, it's even more powerful in that it allows you to block not only scripts but also cookies, ajax, media, etc. And everything per third-party domain.

It is also still possible to reenable support for legacy add-ons. But you'll have to use Developer Edition or Nightly for it to work. Once you are there, set extensions.legacy.enabled to true in about:config. It's also going to be available in the Beta and Release unbranded builds, but not yet.

  • My understanding is that the extensions.legacy.enabled hack was included for testing purposes in pre-release versions only. The code to support the legacy extensions is missing in the actual V57 release. Bummer! – fixer1234 Nov 21 '17 at 19:16
  • @fixer1234, thanks for the info, updated accordingly. – user Nov 21 '17 at 22:17

I installed the "Disable JavaScript" extension and so far it works fine: https://addons.mozilla.org/es/firefox/addon/disable-javascript/

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.