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Sep 11, 2013 - 2 minute read - Evil Tester Technical Testing

How to Turn on and off JavaScript in Firefox

Whoa, I turn my back for a couple of months and Mozilla remove the option to switch off JavaScript in Firefox.

Short version: Install QuickJava or type “about:config” as the URL then search for “javascript.enabled”

We spent a good 5 or 10 minutes thinking we were crazy. “I’m sure the option used to live here…”

As ever, Google came to the rescue..

Why did Mozilla do this? Because of “Checkboxes that kill your product".

Unfortunately, as a tester I still experience moments where I need to kill the product, so How can I do that now?


Firefox has the built in “about:config” which you can type into the URL entry field. Then search for “JavaScript” and click on the “javascript.enabled” to switch JavaScript on and off.


One of the official forum Q&A items mentions an add on called QuickJava, just make sure that enable the “Add on bar” from the toolbar menu “View Toolbars Add-on bar”

Other plugins mentioned in this other official forum Q&A item

I chose to install QuickJava because it lets me toggle a bunch of things quickly.

End Notes

As an opinion, I find it a bit odd that since Browsers make ever more developer functionality available at the click of a mouse to every user: allowing them to edit the DOM, or execute arbitrary JavaScript, or amend and delete cookies, etc. etc. I don’t think I’d make switching JavaScript off a hard thing to do - this is one of the few things I actually do, as a user, to make a misbehaving website behave.

But hey ho. Testers have had it worse - remember when we used to have to same html to the desktop to edit it? And edit actual cookie files? We have it easy - particularly when you get to discover a new helpful add-on that you didn’t know about - QuickJava.

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