CyberNotes
Web Browser Wednesday

One of the major reasons Firefox is approaching 400 million downloads is because of how customizable the browser is thanks to extensions. In a way Firefox extensions are bittersweet, because they can provide some unique and useful features, but at the same time they can cause some unwanted problems.

It’s been well over a year since I last took a look at the issues some popular Firefox extensions caused. Most of the extensions listed there caused crashes, memory leaks, and excessive CPU usage. Since then, a Leak Monitor extension has been created to notify users when a certain type of memory leak occurs. This has successfully helped dozens of developers eliminate memory leaks in their extensions.

Unfortunately not all of the problems have not been solved when it comes to the extensions. Some can still cause Firefox to crash, leak memory, or make your CPU usage skyrocket. Today I thought that I would revisit the current status of extensions to see which ones are still causing the problems.

Firefox Memory LeakTo find the extensions that have problems, I turned to the Mozilla Knowledgebase as well as their bug tracker. I was able to uncover more than a dozen extensions that have performance related issues, and I’m assuming you’re using the most recent versions of the extensions as well as the latest version of Firefox. You’re sure to have even more problems if you’re using older versions of Firefox or extensions that are outdated.

Below is the list that I came up with, and along with each extension I mention the issue along with any known fixes.

Note: You may or may not experience the problems mentioned. If you haven’t had a problem with an extension there is no sense in removing it.

  • Adblock
    Issue: Has been known to crash Firefox when trying to use Gmail Chat.
    Fix: None available right now. It’s recommended that the extension be removed if you use Gmail Chat.
  • All-in-One Gestures
    Issue: Can cause Firefox to crash, and conflicts with the inline spellchecker on Linux and OS X.
    Fix: None available right now. It’s recommended that the extension be removed if you’re using Linux or OS X.
  • Fasterfox
    Issue: Can interfere with website access, and problems may continue even if Fasterfox is removed.
    Fix: Reset the defaults or start with a new profile in Firefox. Also make sure that you have prefetching disabled in the extension.
  • Firebug
    Issue: Causes excessive CPU usage
    Fix: Disable Firebug when it’s not being used, or create a separate profile to use it in.
  • ForecastFox
    Issue: Memory leaks due to satellite imagery.
    Fix: It’s recommended that the extension be removed, or you can install an older version without the satellite imagery.
  • Google Browser Sync
    Issue: Causes excessive CPU usage with GIF animations.
    Fix: None available right now. It’s recommended that the extension be removed.
  • Google Web Accelerator
    Issue: Crashes Firefox when closing the browser.
    Fix: None available right now. It’s recommended that the extension be removed.
  • IE Tab
    Issue: Memory leaks
    Fix: It’s recommended that the extension be removed, or you can install IE View Lite as an alternative.
  • Loki
    Issue: Memory leaks
    Fix: None available right now. It’s recommended that the extension be removed.
  • Media Player Connectivity
    Issue: Causes Unresponsive Script Warnings
    Fix: None available right now. It’s recommended that the extension be removed.
  • Mouseless Browsing
    Issue: Causes excessive CPU usage
    Fix: None available right now. It’s recommended that the extension be removed.
  • SessionSaver
    Issue: Memory leaks
    Fix: Use Session Manager instead.
  • Tabbrowser Extensions (TBE)
    Issue: Slows down Firefox, conflicts with other extensions, and can stop Firefox from working.
    Fix: It’s recommended that the extension be removed, or you can install Tab Mix Plus instead.

People running Firefox 3 right now should be careful if using the ForecastFox or FoxClocks extensions. Both of those are known to have memory leaks (ForecastFox report here and FoxClocks report here).

The extensions that I’ve listed above are all currently known to have some sort of problem. The bad news is that not all of the extensions have been as thoroughly tested as the ones mentioned here, and that’s because Mozilla relies on people like you to submit bug reports when you encounter an issue. If you frequently notice memory leaks, try a fresh Firefox profile, and then install the extensions one by one until you find the culprit. The odds are pretty good that the leak will be the result of one of your “more complex” extensions, and so you may want to start with those.

Additional resources from Mozilla include the Reducing Firefox Memory Usage page and the long list of Problematic Extensions.

There Are 77 Comments

  1. All-in-One Gestures = get Opera

  2. ah-ha! so All in One Gestures is the source of my OS X spell check problem.

    i’ve generally come to live with the fact that FF is a memory hog. i’m running StatusBarEx (Win only) and Restart Firefox extensions to help deal with this.

    StatusBarEx keeps a little memory use indicator on the status bar. When I see that cross the 200MB mark, I use Restart Firefox which adds a “restart” option to the file menu. after a quick restart, my FF memory is back to a more manageable level (for a little while).

  3. Disable Adblock if you use GMail Chat? Yeah, if you’re the kind of person who chops off their arm if they break a nail…

    Just disable Adblock for the individual website. No need to disable the extension.

  4. I’ve known Roboform cause massive memory spikes (I’m talking about 200mb per visit) when visiting Gmail.

  5. the firebug performance issue is a pain — opening new windows or tabs can be quite slow. i use firebug quite frequently and having to disable/re-enable it all the time is frustrating.

    i hope it’s fixed soon!

  6. Solomon Broad wrote:
    I’ve known Roboform cause massive memory spikes (I’m talking about 200mb per visit) when visiting Gmail.

    You should report that as a bug then.

    bunnyhero wrote:
    the firebug performance issue is a pain — opening new windows or tabs can be quite slow. i use firebug quite frequently and having to disable/re-enable it all the time is frustrating.

    It is a huge problem, and I just create a separate profile to put it in. I don’t use it all that often, but it is definitely a necessary tool for web developers.

  7. Use adblock plus instead.

  8. Hey! Ryan, thanks a lot for this most valuable information! Just discovered your website via Lifehacker’s article on this post, and it’s a pleasure to discocer all other comments as well. I’ve registered to your feed and will be in touch with your news every day. Keep us this clear and interesting work!

    P.S. In the above list, I had two extensions concerned, FasterFox and IE Tab. I agree, the main danger in FasterFox is prefetching, let’s avoid that! but other settings have proven in my config to be positive. As for IE Tab, I have removed it, since in fact it being listed here only achieved to convince me of what I had always presumed, a memory hog.

    All the best!

  9. any replacement for “All-in-One Gestures” on Mac OS X?

  10. I’ve cybermarked this article. gonna post it on stumbleupon. excellent

  11. Get rid of Adblock and use Adblock Plus instead. It’s better even without the leak.

  12. I have an easy fix for Adblock: use Adblock plus. Who seriously uses Adblock anymore?

  13. All in One Gestures works fine for me. My Firefox seems to use normal RAM amounts (between 40-150mb, depending on tab amounts) even when I use gestures.

  14. Many folks are using regex rules in Adblock Plus, which just pigs recent versions out (it was rearchitected a few months ago.) Switching to non-regex rules can now dramatically improve Adblock Plus performance.

    Consolidating tools also yield improvements. Lots of addins are repackaged Greasemonkey or Stylish scripts, so just use ‘em directly from Greasemonkey or Stylish & save the additional overhead.

    Finally, if you’re not using it don’t load it. If an addin is only used once in a blue moon then consider loading it only when you specifically need it, not having it unnecessarily active all of the time.

  15. Luckily, I never have to worry about this w/ Opera :)

  16. how to create new profile?? :?: :?:

  17. LAi wrote:
    how to create new profile?? :?: :?:

    Start FF with command
    firefox.exe -p

  18. Ad Block Pro has no difficulties with G-mail Talk.

    And to think you wrote this article yesterday…

  19. For Firebug, is it enough to disable it with its own “Disable” menu item, or do you need to disable it in the “Add-Ons” dialog?

    Many thanks.

  20. Tinhed wrote:
    I’ve cybermarked this article. gonna post it on stumbleupon. excellent

    We’ve gotten an insane number of hits from StumbleUpon…so it looks like that did some good! :) Thanks!

    Michael Maggard wrote:
    Many folks are using regex rules in Adblock Plus, which just pigs recent versions out (it was rearchitected a few months ago.) Switching to non-regex rules can now dramatically improve Adblock Plus performance.

    Consolidating tools also yield improvements. Lots of addins are repackaged Greasemonkey or Stylish scripts, so just use ‘em directly from Greasemonkey or Stylish & save the additional overhead.

    Finally, if you’re not using it don’t load it. If an addin is only used once in a blue moon then consider loading it only when you specifically need it, not having it unnecessarily active all of the time.

    Thanks for the tips! I’m sure the readers will appreciate them.

    netster007x wrote:
    Luckily, I never have to worry about this w/ Opera :)

    That is true, but I’ve noticed some of the widgets can increase your memory usage, too. I don’t use any of those though.

    Kevin wrote:
    Ad Block Pro has no difficulties with G-mail Talk.

    And to think you wrote this article yesterday…

    I’m sure there are some people who still use the standard Adblock, and we were just trying to be thorough. Sorry if you don’t approve. :|

    Steve wrote:
    For Firebug, is it enough to disable it with its own “Disable” menu item, or do you need to disable it in the “Add-Ons” dialog?

    Many thanks.

    If Firebug doesn’t appear disabled in the Add-ons dialog you’ll want to disable it there as well. That way Firefox ignores it all together.

  21. Yeah, I hardly ever use widgets either. I have a universal bittorent one and a bug me not one. I’ve never seen any really cool widgets for Opera, like a CPU monitor or bandwidth test or anything.

  22. netster007x wrote:
    Luckily, I never have to worry about this w/ Opera :)

    Of coz, “no brain – no pain”.No features – no problems related with these features. Surely. Opera is a binary blob and you can’t extend it’s feature set with extensions like you can with Firefox.

  23. Opera has plenty of features. Far more than I had w/ Fx even with extensions (but of course even then I didn’t install too many ext’s because I wanted my browser to function). In Opera, I get a ton of features out of the box, the ability to customize any toolbar, and add new ones from a selection of hundreds of buttons, I can use Opera userscripts and Greasemonkey scripts, I can download widgets, plus I can block ads using a universal filter, and download bittorents. Since I can do all this in Opera w/out extensions, I can have tons of features and customization w/out sacrificing performance or stability.

    From my experience, using several extensions can make Firefox releases less stable than nightlies.

    Heres an example of how an innovative, unique feature in Opera helps make browsing better. I was watching 24 online streaming. The episode was broken up into 3parts, which would have meant constantly tabbing between windows in Fx to monitor each’s buffer progress. But, since I was using Opera, a simple click to cascade and I could monitor all at once. Then, once they’ve buffered fully, I can use Opera’s true full screen mode (just shows page content, 0 toolbars) to complete the experience. Opera rules!

    [farm2.static.flickr.com]

  24. I love that Opera supports MDI (Multiple Document Interface) so that you can tile and cascade the windows. I use that feature all of the time, and it’s something I feel Firefox has always missed. Unfortunately Firefox would essentially have to be rewritten from scratch to support the same feature.

  25. netster007x wrote:
    Opera has plenty of features. Far more than I had w/ Fx even with extensions

    But Opera does has FIXED SET of features. And their “widgets” thingie is pretty lame since it does not allows to alter browser behavior in significant manner.

    With Firefox it is up to YOU to pick features YOU need, not features “THEY” (browser authors) think you need. So you can enjoy bu using program. While there is fewer features by brute count, there will MUCH MORE features USED BY YOU when you selected add-ons yourself since you pick only what you need. What is the clue in features count if you do not need ‘em? I do not need mail, irc or torrent in my browser, I have my favorite apps for these tasks and these features are just wasting HDD space and making setup larger.

    As example of add-ons usefulness: there is ErrorZilla add-on for Firefox. When you hit dead site you do not have to see just a boring error message from browser. Instead, you given a choice. You can ping or traceroute server to get idea what’s wrong. Or use Google cache or Wayback Machine to get web site back in cached state (better than NOTHING, right?). Can the Opera do the same? No? Phew, typing long thingies by hands for each dead URL is dumb and boring thing.

    And I did not noticed anything comparable with AdBlock Plus – nice AdBlocker with updateable block-lists and which is so comfortable to use.

    And there is no anything like DTA aka Down Them All – nice downloader which is able to download files via several connections at once and integrates into browser nice, so it can DL all files on current page, etc.

    As well as no things like WebDeveloper add-on. You do not have to be a real developer though, this thing is nice for advanced users as well who wants to take browser under their own control and get funny swiss army knife for the web.

    And NoScript add-on is sort of JavaScript “firewall”.Opera has similar features but these are pretty limited compared to this thing.

    And TabMixPlus is great.You can finally have tabs with behavior YOU like, not THEY think you will like.Actions on different clicks are configurable.As well as where tab closing button(s) are placed.Virtually any aspect of tabbed browsing is tweakable. Did not seen anything comparable in Opera or as any sort of add-ons.

    Not to mention Opera has bunch of issues with web sites rendering of web sites.
    At very least:
    - JavaScript is Opera’s permanent pain in the a$$.Opera treats sites in its own unique way but due to strange marketing it failed to get popular enough to get counted by webmasters worldwide.Some sites are looking pretty broken or some features are not working or malfunctioning.These which rely on JavaScript is first example
    - As another bad thing, Opera does not supports non-integer relative positioning in CSS. So, if web master wants to place elements by relative sizes in percents… well, opera will ignore non-integer part of percents. Let’s adimt that 1% on modern monitor is pretty decent value, usually between 10 to 16 pixels. So…if you like when www looks like if it was crafted by an axe and by the hammer, Opera is a right choice. Othervice … try to ask webmasters, they will tell you what they think about Opera. Prepare to hear something non-printable though. Beware, you can hear foul language, 18+ only! :)

  26. Argh, forgot to mention, Opera is proprietary blob. So it released only when (and if) Opera Software will decide to do so. And if they’ll decide do not release or do not support something, nobody can override this. As a reasonable consequence there is no Opera for my favorite OS (x64 Kubuntu) at all. Cool, isn’t it? These guys are still refusing to support x64 platforms. Why they’re thinking I will run legacy 32-bit binary blob? Nope, I will not. Fortunately there is native x64 port of my favorite Firefox though ;)

  27. I blogged about this a while back.

    [blog.genotrance.com]

    I still hit 200-300MB at times but that’s cause I don’t restart Firefox for days and run several tabs at a time, especially when I’m catching up on my feeds. IE is just as bad though, so the high memory usage seems to come with the territory…

  28. Dude wrote:
    Argh, forgot to mention, Opera is proprietary blob. So it released only when (and if) Opera Software will decide to do so. And if they’ll decide do not release or do not support something, nobody can override this. As a reasonable consequence there is no Opera for my favorite OS (x64 Kubuntu) at all. Cool, isn’t it? These guys are still refusing to support x64 platforms. Why they’re thinking I will run legacy 32-bit binary blob? Nope, I will not. Fortunately there is native x64 port of my favorite Firefox though ;)

    Opera 9.5 Alpha is going to support the 64-bit platform, and the 64-bit version of Firefox I don’t believe is officially done by Mozilla. I don’t like to use browsers that aren’t official.

    And you made a lot of other good points in your previous post, but you should know that Opera does have web developer tools and completely customizable keyboard shortcuts and mouse gestures. So you can customize what happens, for instance, when you middle-click on a tab. I would say that it has everything Tab Mix Plus does.

    Don’t get me wrong…I use Firefox and Opera on a daily basis, but some of the things you mentioned Opera can indeed do. Most people just don’t give it a fair shot and are rather quick to criticize.

  29. Dude wrote:
    these features are just wasting HDD space and making setup larger.

    Firefox’s setup/space usage is large even without all those features :D

    Dude wrote:
    ErrorZilla … Can the Opera do the same?

    yup. If the error page is a 404 page (generated by server) then you can use UserJS. If the page is generated by opera (standard opera error page) then you can edit your lang file to add links. And you can always edit menus/buttons to add these features ..

    Dude wrote:
    Down Them All

    links panel :)

    Dude wrote:
    WebDeveloper add-on

    [operawiki.info]

    Dude wrote:
    You can finally have tabs with behavior YOU like, not THEY think you will like…Virtually any aspect of tabbed browsing is tweakable.

    Can you restore tabs ? :?:

    Dude wrote:
    Did not seen anything comparable in Opera or as any sort of add-ons.

    because there is no need to use addons for those features.

  30. Ayush wrote:
    Dude wrote:
    You can finally have tabs with behavior YOU like, not THEY think you will like…Virtually any aspect of tabbed browsing is tweakable.

    Can you restore tabs ? :?:

    Yes, with Session Manager.

  31. Zac wrote:
    Ayush wrote:
    Dude wrote:
    You can finally have tabs with behavior YOU like, not THEY think you will like…Virtually any aspect of tabbed browsing is tweakable.

    Can you restore tabs ? :?:

    Yes, with Session Manager.

    Minimize/Restore/Maximize :D

  32. To you Opera lovers…

    Does Opera have a google bookmarks extension (ala gmarks)? Opera’s inability to easily allow me access to google bookmarks across any of my computers I’m on makes it no-go. As far as I’m aware they don’t even have a concept like “foxmarks’ which lets you synch your bookmarks to a central repository and keep all you computers in sync (I’m mostly on my mac, but sometimes on a linux box at home, and at work I’m on windows, I like having all my bookmarks easily all synched without having to think about it. Personally I like google bookmarks bc the tag concept makes the most sense to me.)

  33. Rick R wrote:
    To you Opera lovers…

    Does Opera have a google bookmarks extension (ala gmarks)? Opera’s inability to easily allow me access to google bookmarks across any of my computers I’m on makes it no-go. As far as I’m aware they don’t even have a concept like “foxmarks’ which lets you synch your bookmarks to a central repository and keep all you computers in sync (I’m mostly on my mac, but sometimes on a linux box at home, and at work I’m on windows, I like having all my bookmarks easily all synched without having to think about it. Personally I like google bookmarks bc the tag concept makes the most sense to me.)

    Opera 9.5 (currently in Beta) has a feature similar to Foxmarks that is built-in. It synchronizes your bookmarks with their own server so that you are not relying on a third-party for storing them.

  34. My Firefox 2.0 has been crashing every day, more often than performing properly. I can barely use the browser. Mozilla, please rebuild your browser, as I certainly am not planning to download fx 3, for even more bloat.

  35. surfing the net i use firefox however watching videos on youtube, metacafes, etc i use google chrome browser now. Google Chrome is very stable for any site that use heavy flash, javascript, and videos stuff like that. even playing yahoo games is best on Google Chrome but not firefox

  36. If you have witnessed multiple ‘hulu.com’ tabs opening on your firefox then Disable the extension ‘FireSay’

Leave Your Comment


Message is the only required field.
Emails are not published.