How Can I Stop Scripts on a Page in Firefox?

Question

How can I stop scripts on a page in Firefox? I don't care if the solution is draconian. Super-tech-savvy solutions are also fine.

Clarification: I don't want to turn off scripts permanently. I want to be able to kill a script (or all active scripts) on-demand for a given web page.

Solution 1

It's been answered on a later question. For short:

• Open the developer console from the menu or by F12.
• Click the debugger tab.
• Click the pause button.

Solution 2

Pressing ESC worked for me as suggested by @simlev. For me, it was a page where a blocking pop-over would be displayed in 5-10 seconds after the page was loaded. Pressing ESC effectively stopped the JavaScript on that page. This wouldn't be a replacement for extensions like NoScript, but could be handy in similar situations.

Update on 10/2020: Given the multiple comments about how pressing ESC does not work, one should not have much hope with this method. As stated before, this worked only for a specific case; however, I guess it does not hurt to try just to see if works for you - without much expectation.

Solution 3

Firefox developer console has a ⏸ pause button and a Disable JavaScript setting, which is very effective:

Firefox Developer Console

• In case you don't want any JavaScript to run, first disable it then refresh page (F5).
• In case you want it to run just until a given point, use the ⏸ pause button in the debugger tab.

You can open the developer console for a given page form the menu, with F12, or with one of this shortcut combinations: Shit + Ctrl/⌘ + K/I

Comments

[Arkadiusz Drabczyk]

noscript.net

[simlev]

Pressing ESC stops script execution.

[Oskar Skog]

Pause, abort or disable? If you want to temporarily enable JS you should use NoScript.

[Admin]

Pressing ESC WILL NOT stop ReactJS from executing.

[LonnieBest]

@simlev Pressing ESC does NOT stop script execution.

[JKAbrams]

This does not work. Sites still show up with high CPU usage in about:performance after after pressing ESC

[dojuba]

Well, this was not an absolute definite answer but merely 'one' possible answer that worked for me and obviously for some others. Clearly, the answer will depend on many factors, such as browser, JS framework etc.

[Jose Manuel Abarca Rodríguez]

In my case, ESC stops the loading of page but not the execution of JS.

[simlev]

I didn't think much clarification would be needed, but the tone of some comments says otherwise. Pressing ESC stops page loading, as @JoseManuelAbarcaRodríguez correctly explains: if you time it right after the page contents are displayed but before the unwanted scripts are loaded, you effectively prevent them from running. This can be useful in some scenarios and is IMHO relevant to the question.

[Adam Jagosz]

Doesn't work when the script enters an infinite loop which is what I want to stop (or if it works, then with a lot of delay).