Can uBlock Origin Block WebRTC?

#1

Post by justusw » Mon, Jul 27, 2026, 3:01 AM UTC

Can uBlock Origin Block WebRTC?
justus.pw

Re: Can uBlock Origin Block WebRTC?

#2

Post by justusw » Mon, Jul 27, 2026, 3:01 AM UTC

Perhaps someone here knows how to make uBlock Origin block STUN/TURN connection attempts to domain names that are in its block list?

Re: Can uBlock Origin Block WebRTC?

#3

Post by its-summertime » Mon, Jul 27, 2026, 3:18 AM UTC

No it can't, but yes it can, just not like that.

https://github.com/gorhill/uBlock/wiki/Resources-Library#now...

As can be seen, it matches on the source, not the destination

https://github.com/gorhill/uBlock/wiki/Resources-Library#web...

can match on the destination, however.

Its not a good state of things, but I'm assuming its more of an issue on the browser side as opposed to the extension side

Re: Can uBlock Origin Block WebRTC?

#4

Post by justusw » Mon, Jul 27, 2026, 4:35 AM UTC

its-summertime wrote: post #3

No it can't, but yes it can, just not like that. https://github.com/gorhill/uBlock/wiki/Resources-Library#now... As can be seen, it matches on the source, not the destination https://github.com/gorhill/uBlock/wiki/Resources-Library#web... can match on the destination, however. Its not a good state of things, but I'm assuming its more of an issue on the browser side as opposed to the extension side

Thanks for the reference links. I blocked RTC connections initiated on the SBI Shinsei banking log in page at bk.web.sbishinseibank.co.jp with the following custom uBlock Origin filter:

    bk.web.sbishinseibank.co.jp##+js(nowebrtc)

You can see that it works because typing `new window.RTCPeerConnection()` in the browser console prints this:

     Document tried to create an RTCPeerConnection:  undefined

Which comes from uBlock, see https://github.com/gorhill/uBlock/blob/5efb8ee4891c09720011e...

Edit: I gave a shout-out to your comment on the blog post linked in this submission. Thanks again.