A bizarre bug in Firefox has cropped up that means users of Firefox are unable to load any website in the Mac, Windows and desktop Linux versions of the browser.
While the developers work on a solution to the bug, there is a fix you can apply to workaround the issue …
Affected users are simply seeing their tabs spin forever, never completing loading to show the page.
The underlying issue preventing pages from loading appears to be an infinite loop bug in Firefox’s HTTP3 implementation.
This essentially causes the browser process to hang indefinitely.
In particular, the current theory is that one of Firefox’s data analytics services recently upgraded to a HTTP3-powered backend and the browser is failing to resolve it successfully.
The actual implementation bug will have existed for a while but it has only come to the fore because Firefox attempts to connect to data analytics servers almost immediately after launching the app.
Luckily, very few real websites actually care about HTTP3 with almost everyone either still using older standards, or providing a fallback.
This means HTTP3 capability is not yet required to browse the modern web.