Firefox load slowly webpages after changing DoH settings
Hello fellow Firefox users, I sadly cannot use my Firefox (120.0.1, 64 bits, Windows 10) anymore as it is too slow to show a webpage... It's so slow, that I initially tho… (read more)
Hello fellow Firefox users, I sadly cannot use my Firefox (120.0.1, 64 bits, Windows 10) anymore as it is too slow to show a webpage... It's so slow, that I initially thought that I have no internet connexion at all on Firefox.
Can anyone help me figuring why my Firefox profile is so slow ?
Long story short:
- Until 2023-12-05, my Firefox was working normally.
My parameters were "No HTTPS everywhere" and "No DNS over HTTPS (DoH)".
- On 2023-12-05, I was connected to an entreprise DNS (Mangling DNS).
I cannot acces some website because of their local policy, so I changed my DNS parameters. I choose to use DoH with Cloudflare instead of the given DNS. Internet worked perfectly.
- On 2023-12-06 and 2023-12-07, same parameters, Internet worked perfectly on another network. - Since 2023-12-08, Internet is very slow. It need about 1.5 minute to get start.duckduckgo.com loading on any network.
I thought it will not load at all (timeout ?). Others webrowsers (e.g. : Microsoft Edge) are correctly working. The "ping google.com" command is working normaly on windows with 2ms delay. The DNS on windows "Get-DnsClientServerAddress" are the normal DNS of the router. Even with reverting the DoH parameter to off, I do not get back my web browsing speed.
Troubleshooting :
- It's slow with "DoH and Cloudflare" activated.
It's slow on my home network. It's slow on a public network. It's slow on another private network. https://www.dnsleaktest.com gives me a list of Cloudflare DNS (IPv4) near me, different from the DNS (IPv6) used by Windows 10. Meanwhile, Microsoft Edge, ping and wget/curl are working normally (i.e. no delay). Noticably, Microsfot Edge use by default according to https://www.dnsleaktest.com the same Cloudflare DNS.
- It's slow with "DoH and Cloudflare" NOT activated.
It's slow on my home network. It's slow on a public network. It's slow on another private network. https://www.dnsleaktest.com gives me one DNS from my ISP (IPv4), same value as the DNS (IPv4) used by Windows 10. Meanwhile, Microsoft Edge, ping and wget/curl are working normally (i.e. no delay). Noticably, Microsfot Edge use by default according to https://www.dnsleaktest.com the Cloudflare DNS.
- In about:crashes there is not relevent crash (only old crash).
- I have not changed any about:config parameters in the 2023-12-05 to today (2023-12-12) period.
- I have run mozregression GUI with no problem.
The program oppened succesfully start.duckduckgo.com . This website was choosen as it is an allowed website on every DNS. Firefox nightly (mozilla-central) 2023-06-02 : good Firefox nightly (mozilla-central) 2023-09-03 : good Firefox nightly (mozilla-central) 2023-10-20 : good Firefox nightly (mozilla-central) 2023-11-12 : good Firefox nightly (mozilla-central) 2023-11-24 : good Firefox nightly (mozilla-central) 2023-11-30 : good Firefox nightly (mozilla-central) 2023-12-03 : good, show a message saying more or less "Nightly started with no extension" Firefox nightly (mozilla-central) 2023-12-04 : good Firefox nightly (mozilla-central) 775ade8b : good Firefox nightly (autoland) 87d12c4b : good Firefox nightly (autoland) ba8757a7 : good
- Firefox 120.0.1 is saying that it is up-to-date.
And as of today, it is.
- I do have some extensions (12 activated) on my Firefox, so I try without extension.
It worked but I do not understand why! * New profile. Using "firefox.exe -profile" I created another clean profile to see. It worked. According to https://www.dnsleaktest.com, my new empty profile uses both Cloudflare DNS (IPv4) and the router DNS from the ISP. Adding one-by-one most of extensions (6 now) to this new profile do not break yet my Firefox speed. * Safe Mode. Using "firefox.exe -safe-mode" I have started my corrupt profile without extension, JIT, etc... It worked. According to https://www.dnsleaktest.com, it uses only the router DNS (IPv4).
- I can send some result from about:support if needed, but it kills privacy...
Conclusion :
I do not understand why my main Firefox profile is not working correctly. I do not see strange things when troubleshooting. Nothing makes sense.
May someone help me figuring out?
Regards, eliotlencelot.