Why are Google sites so slow on Firefox?

This effect has been mentioned many times on HN. Some comments attribute it to Google intentionally slowing Firefox to make Chrome seem faster. Some comments attribute it to Google utilizing API's in Chrome that they have specifically optimized to make gmail faster that are not so "specially optimized" in Firefox.

In the end, only the Google chrome and gmail teams can answer the true why, everything else is guesswork on everyone's part.

As to youtube, as with @PaulHoule) I too have not noticed any slowness, but my use of youtube in firefox is only to obtain the URL to hand off to yt-dlp (youtube-dl successor). Watching videos with my local client player is worlds superior to playing a stream in any browser (Firefox/Chrome/otherwise) that I simply do not play the streams in Firefox from youtube at all.

Google is engaging in anti-competitive practices. E.G. Some nature docs I purchased unfailingly have "licensing issues" on YouTube on FF, but magically work on Chrome.

If you're experiencing very slow (60 seconds) page loads on POST, this may be a Firefox bug [1] interacting with Google's TLS settings. If the pages are just kind of sluggish, I dunno.

The really short version is go to about:config and disable security.tls.enable_0rtt_data; the pretty short version is if you need a new HTTP/2 connection to make a POST request, and the server supports TLS 1.3 Early Data (aka 0rtt), and Firefox negotiates Early Data, it won't send the POST until an inactivity timeout occurs on the TLS socket. In Firefox 94 (in release channel 2020-11-02), that timeout was about 60 seconds; looks like the same for Firefox 95 (in release channel as of 2020-12-07). Firefox 96 (currently available as Nightly, expected release 2021-01-10) had a shorter timeout of 4 seconds, but also has a bug fix as of 2021-11-26.

Of course, it's difficult to tell which client is which during the TLS handshake, so you can't really offer most clients TLS 1.3 Early Data and not to broken versions of Firefox; not that Chrome uses TLS 1.3 Early Data.

https://bugzilla.mozilla.org/show_bug.cgi?id=1740856

I watch Youtube with Firefox all the time (on both Windows and Mac) and don't perceive any problems.

Google Meet is unusable on Firefox... about 1/3 of the time, 30-50min into a meeting, my whole computer starts to freeze up. Using Chrome fixes it. So now I have Chrome on my computer and use it exclusively for Google Meet (I have to use Google Meet for work).

This happens even with all my browser extensions turned off.

I find it very frustrating.

Maybe because YouTube uses Polymer. Firefox didn't used to support web components so Polymer had to use polyfills. I'm not sure they ever updated it and now it seems like Polymer has been abandoned? My best guess anyway. Should be fairly easy to verify.

This has been my experience too, may possibly be from an old Android version. I never dug in deeper but one of these old beater phones I keep around for random around the house use is where I experience this Chrome : Firefox discrepancy.

What extensions do you have installed? I've seen adblockers slowing down browsers significantly if anything other than uBlock Origin is used.

I've personally noticed them work faster with Firefox than Chrome (macOS Monterey, Firefox 95)