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

This thread was archived. Please ask a new question if you need help.

Firefox 79 is extremely slow

  • 1 reply
  • 1 has this problem
  • 7 views
  • Last reply by FredMcD

not4moi-mozilla
not4moi-mozilla
more options

Since upgrading to Firefox 79 many Web pages are noticeably, irritatingly slower: Slow to load, and especially for interactive pages (Javascript, etc), slow to respond. Some are teeth-grindingly, give-up-on-Firefox slow.

I've downgraded twice to Firefox 77 and the slowness went away, but that isn't a choice anymore on my work computer.

Please get rid of whatever "improvements" have ruined version 79 and restore the performance of my preferred browser.

Since upgrading to Firefox 79 many Web pages are noticeably, irritatingly slower: Slow to load, and especially for interactive pages (Javascript, etc), slow to respond. Some are teeth-grindingly, give-up-on-Firefox slow. I've downgraded twice to Firefox 77 and the slowness went away, but that isn't a choice anymore on my work computer. Please get rid of whatever "improvements" have ruined version 79 and restore the performance of my preferred browser.

All Replies (1)

FredMcD
FredMcD
more options

Start Firefox in Safe Mode {web link}

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?


https://support.mozilla.org/en-US/kb/firefox-slow-how-make-it-faster

https://support.mozilla.org/en-US/kb/firefox-uses-too-many-cpu-resources-how-fix

https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-ram

https://support.mozilla.org/en-US/kb/firefox-hangs-or-not-responding

https://support.mozilla.org/en-US/kb/firefox-takes-long-time-start-up

https://support.mozilla.org/en-US/kb/quick-fixes-if-your-firefox-slows-down


MemTest LAST UPDATED : 27/09/2013 Could you please run a tool from http://memtest.org/ in order to check the integrity of your RAM?

You will need a thumb or disk drive to install it on.


Do you let Windows handle the page file or did you set a fixed size ? If you use a fixed size for the page file then try the former and let Windows handle the page file.