Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Èròjà atẹ̀lélànà yii ni a ti fi pamọ́ fọ́jọ́ pípẹ́. Jọ̀wọ́ béèrè ìbéèrè titun bí o bá nílò ìrànwọ́.

Firefox load slowly webpages after changing DoH settings

  • 1 èsì
  • 0 ní àwọn ìṣòro yìí
  • 9 views
  • Èsì tí ó kẹ́hìn lọ́wọ́ zeroknight

eliotlencelot
eliotlencelot
more options

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.

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.

All Replies (1)

zeroknight
zeroknight
more options

You can run mozregression with your main profile that has the problem, make a backup of it first though.