GrapheneOS adds a permission to chromium on android so you can manually allow websites to have their javascript JIT'd. Most websites are plenty quick without the JIT although SPAs like Tinder and Google Maps did struggle without it.

I use Bromite which does the same and the only issue I run into is when sites need WASM. (Chromium doesn't have a non-JIT WASM interpreter, though IIRC Edge does.)

Would this prevent me from looking at or modifying the Javascript code that is running, since it's already compiled?

This is a completely different thing.

The "super duper secure mode" is not at all about you accessing or modifying the JS code from a website you are visiting. What it is about is trying to protect against some piece of JS code bypassing the security of the browser sandbox and accessing stuff it shouldn't ever have access to.

:)

Edit: Also, in general, no, disabling JIT would not prevent any particular JS code or extension from running. At most, it might mean some code would run slower. But that's what they claim, that it isn't noticeable.

Thanks for the clarification.

Hmmm. Maybe I misunderstood the link or missed something. I thought all they did is disable JIT and leave the JS as interpreted.

I'm not knowledgable with JS at all, so you're probably right. I do wonder what the "Code Integrity Guard" is going to mean - who has to sign the JS? Does this mean tampermonkey/adblock scripts would stop working? Genuinely asking as like I said I don't really know too much about javascript

This seems to be referring to https://docs.microsoft.com/en-us/microsoft-365/security/defe... which would mean that they require the browser itself to be digitally signed, not the JS.