Latest Mozilla Meeting Reveals Firefox 4 Performance, Stability Issues

Martin Brinkmann
Feb 17, 2011
Updated • Mar 2, 2015

The latest meeting notes of Mozilla Firefox's development team seem to suggest that the last two beta releases of Firefox 4 have caused an increase in performance and stability issue reports by users of said beta versions of the web browser.

Mozilla notes that there has been a "huge increase in daily comments about memory and CPU usage" and that users reported that Beta 11 of the Internet browser felt slower than Beta 10.

The feedback summary lists several heavily reported issues, from constant reloading on Hotmail and Flash related crashes on Facebook and on Gmail, over font rendering issues on Windows and Gmail lock ups to the inability to switch search engines and broken Facebook chat.

Other users reported constant reloading on Hotmail or that the Panorama feature of the browser is completely broken.

A closer look at individual user feedback shows that some users have experienced memory usage of up to 1.4 Gigabytes and 100% cpu usage. The majority of users are however reporting memory usage of a few hundred Megabytes which appears to be in the norm.

It is not clear yet how the team will react on the increase in reports. Mozilla aims for a March release of the final version of Firefox 4, a doable task with only 8 open blockers left of which seven have a patch ready. The performance and stability issues on the other hand could in worst case postpone the release of the browser once again.

The coming days will show how the developers react: Will there be another beta or will they be able to fix the issues in the release candidate of the browser?

Have you worked with the latest Firefox 4 beta? Let us know what you think of it.

Update: We removed a link from the article as it was pointing to a page on the Mozilla website that is no longer available (that indicated the memory usage).


Tutorials & Tips

Previous Post: «
Next Post: «


  1. Liana Badea said on May 31, 2011 at 4:21 am

    I can’t use SEO Toolbar in Firefox 4, that sucks. Also not compatible with other important tools. Tried beta 10, 11, not working for me, so I had to go back to older version 3. Not to happy about it.

  2. pitman said on February 20, 2011 at 7:35 am

    While I don’t have any crashes I do seem to have an increased memory usage up to 1GB with only a few (4-7) tabs open.

    1. Steven Monrad said on March 17, 2011 at 6:27 pm

      Firefox 4 Beta many problems, AVG doesn’t work, Gmail message printing doesn’t work, etc. etc.
      Previous Firefox fine.
      Neither Chrome nor Opera will allow a complete history erase setting as in Firefox 3.
      Looking to unininstall FF 4 and reinstall FF 3.

  3. Mystique said on February 18, 2011 at 3:03 pm

    I’m mystified by people claiming to have issues such as crashes and the like with firefox, I hardly ever have problems with firefox (v3.6.13). Go with whatever works for you and makes you happy.

  4. Vardenis said on February 18, 2011 at 9:41 am

    Hell I’m switching to Opera. I’m tired from endless crashes of ff, and buggy plug-ins :(

    1. Mushaf said on February 18, 2011 at 9:45 am

      Why not switch to Chrome?

  5. Crodol said on February 17, 2011 at 11:40 pm

    The reason I use 3.6 and started using Opera more and more.

  6. Pishaw said on February 17, 2011 at 9:48 pm

    I’ve been a Fx user for years, and am using 4b11 now. I love the new interface, I’ve experienced no stability problems. But the ram usage is out of control. After on hour online, it’s up to 450mb.

    I have enough ram for this. But people running XP with a gig of memory, all they know is that when they run the Firefox beta, the machine runs slow. Mozilla REALLY needs to address this.

  7. Mushaf said on February 17, 2011 at 9:47 pm

    There’s definitely some memory usage issues with beta 11. Yesterday I tested it and noticed the memory consumption to be too high. With only 5-6 tabs opened my memory usage rose upto 350 MB, while the present stable build (v3.6.13) on my machine hardly goes over 150 MB with 10-15 tabs opened.

  8. Ahmad said on February 17, 2011 at 8:41 pm

    I also felt that Beta 10 was faster than Beta 11.

Leave a Reply

Check the box to consent to your data being stored in line with the guidelines set out in our privacy policy

We love comments and welcome thoughtful and civilized discussion. Rudeness and personal attacks will not be tolerated. Please stay on-topic.
Please note that your comment may not appear immediately after you post it.