Saturday, March 21st 2009

Once More: Firefox 3 is Not Bloated

Just in from the insane-browser-prophecies department:

Despite the fact it’s not really ready for human consumption, Chrome has won. Firefox is already dead. The only way the situation can be altered is for Mozilla to slam on the brakes, lean out of the window of the truck, apologize for going the wrong way, and turn around. But that’s unimaginable.

Kier Thomas


Well, that will only be true if all Firefox users migrate to Chrome. Why would they do that? Chrome does not provide any advantages that seem significant enough for a long-time Firefox user to switch.

If you consider how many Firefox users that have special extensions installed the above scenario seems even more unlikely. Even if Chrome did have equivalents for all the Firefox extensions, it doesn’t provide enough benefits to motivate the hassle of swapping out Firefox.

And what has Mozilla to apologise for? Ripping up Microsoft’s monopoly? Opening the doors for standards based coding?

Kier and others are making out that Firefox has become bloated and slow. So I decided to do a quick comparison of the different releases of Firefox on my four year old AMD 3200+ Windows XP PC.

I installed Firefox 1.0.8, Firefox, Firefox and Firefox 3.0.7.

Installation files for Firefox 1, 1.5, 2 and 3.

I set up a clean profile for each version and set them to open a blank page by default. Then I made sure to close all other programs and launched each version of Firefox five times in a row, timing the launches with a stopwatch. (From hitting Enter to seeing the big white browser window.) And then I repeated the whole process so I got ten values for each browser.

I tested my reaction time which was 0.23 seconds on average and subtracted this from all the measured times.

So here is a visual comparison of the launch time for the different versions of Firefox since 1.0 (averages of ten measurements):

Start-up times for Firefox 1.0, 1.5, 2.0 and 3.0 on a Windows XP AMD 3200+ system.

Firefox 1 took just over 0.5 seconds on average. Firefox 3 takes 0.6 seconds. That’s a difference of 0.1 seconds on a four year old system. On a newer system the difference will be even smaller.

I also tested the cold launch times, by rebooting windows between each startup. These are averages of five start-ups:

Cold launch times for Firefox 1.0, 1.5, 2.0 and 3.0

Here the pattern is the opposite. Firefox 2 launches faster than 1.5 which launches faster than 1.0. Firefox 3 launches slightly slower than version 2 but is still a few seconds better than version 1 and 1.5.

I also tested average page loading times for, a fairly heavy page with plenty of Flash and images.

Average page load times for Firefox 1.0, 1.5, 2.0 and 3.0

Again I did five measurements for each version. Then I repeated the procedure, just to make sure no version was being helped by network caching. (I also loaded the page a few times before starting the test to make sure no browser was disadvantaged by being first.)

Between each page load I cleared all history, browser cache and cookies. So these values should be pretty representative for cold page load times for pages with plenty of images and Flash.


So, Firefox 3 takes roughly 20 percent longer to launch than Firefox 1 for warm starts, which equals at most one or a few tenths of a second. For cold starts (first start after booting your computer) Firefox 3 launches about 30 percent faster than Firefox 1. Also, each page load in Firefox 3 is probably saving you several seconds compared to Firefox 1.

We already know that Firefox’s memory consumption has gone down a whole lot and Javascript speed was improved by a factor of 3 or 4 for version 3.


So could someone explain to me how Firefox 3 is bloated? Is Firefox bloated because it lets you find visited pages easily from the location bar? Is it bloated because it has an industry leading automatic update system? Because it lets you rearrange tabs as you like, because it passes the Acid2 test or because it can remember your tabs from session to session?

Yes, Firefox has added many features since version 1.0. But it just hasn’t gotten bloated in the sense of unnecessary features that get in the user’s way.

Quite the opposite is true in fact. The Firefox developers have thoughtfully added many capabilities to Firefox without forcing mums and grannies to jump through hoops when they want to go on-line. At the same time they have made it load web pages much faster, and cold starts are much quicker. Warm starts are marginally slower.

29 Responses to this post:

  1. Ken Saunders says:

    Awesome post!That was a lot of work and I personally appreciate it. We can hope that others will accept it but that’s doubtful. I just don’t understand how Firefox (and Mozilla) have become the enemy.People just can’t stand success I suppose.

  2. choc fu says:

    awesome, your right why would anyone with firefox even consider any other broswer let alone switch? An awesome blog and much appreciated :)Firefox For Life!

  3. Kevin says:

    Whether the feature gets in your way seems a bit irrelevant. The fact is, Firefox has been packing on features that could have easily stayed as extensions.

  4. David Naylor says:

    Kevin, if those features are useful to 95% of Firefox users, why should they remain as extensions if they don’t get in the way and don’t slow the program down?

  5. Kevin says:

    First how do they Mozilla developers know that feature x is useful to 95% of users? And if Mozilla introduces a feature in a Firefox beta, then all the people who don’t beta test will not have a chance to give feedback.As for features, live bookmarks can slow down Firefox, and the new bookmark and history system in Firefox 3 is known to annoy and/or inconvenience several users.

  6. Anonymous says:

    With people like Kier making bold statements completely unsupported by anything whatsoever, it’s no wonder the IT landscape is a lot like offroading on a lava bed.

  7. Anonymous says:

    Thank you!I’m tired of people complaining that Firefox is old and slow, and that the chrome etc are better.Firefox 3.0 is a great well rounded browser, 3.5 is even better.

  8. Mike Beltzner says:

    This is great data to have, trending across the historical.We always focus on performance; the plurality of our community means that as soon as we start looking at adding to the product, someone else starts asking what we can take away or optimize. It’s a great system, really.Many thanks, David.

  9. David Naylor says:

    Thanks Mike and everyone else for the encouraging words. I enjoy doing this stuff and I’m thinking of doing a similar comparison between …Chrome 2bSafari 4bFirefox 3.1b3IE8and why not Opera 10a while I’m at it?This post has seen a fairly huge load of traffic since I wrote it. Glad to see so many are getting some facts and not just the usual FUD.

  10. Justin Dolske says:

    Yeah, this is a good post. I think people are conflating the addition of features with overall performance, when the two are often quite independent.One suggestion: I groan a little every time someone uses “benchmark” and “stopwatch” together. Too much can go wrong (although even as a coarse approximation the data supports your overall point). Maybe use a shell script that prints the time, then launches a browser with a homepage set to javascript:alert( Startup time is an inherently fuzzy thing to measure, of course.

  11. David Naylor says:

    Thanks.I didn’t really call this a benchmark until others did though.The variances in the tests where small – the actual times were always pretty close to the averages in the graphs. Even for the warm starts the differences between browsers were clear, though small.I’m pretty confident most of the differences would have checked out with a real statistic analysis.The reason I didn’t do what you just suggested was because I simply didn’t think of it. Might give it a try. Shouldn’t be too hard, even with my limited hacking skills.

  12. Chris says:

    I agree that Firefox definitely isn’t bloated, but get a few tabs open (I routinely have 10+ tabs open) and it does get slow. This is where Chrome has a huge advantage, with its out-of-process architecture. Chrome may not really be any faster in measurable terms, but it ‘feels’ faster. Having worked with the mozilla code of recent, I can say I’m very impressed with how far it’s come, how well it renders and how little memory it uses, but you can only go so far when you do everything in a single thread. The fact of the matter is Firefox blocks the entire UI for short-but-noticeable periods of time when I do just about anything; scrolling, clicking on links, loading pages, loading plugins, opening new tabs, closing tabs… It ‘feels’ slow because of this.I still use it over Google Chrome though 🙂

  13. Peregrino says:

    I think all this stuff about “firefox is bloated” comes from the fact that Chrome is being developed by Google, and advertised even inside your mind.I wonder whether if Chrome had been developed by an small, unknown company and minimally advertised the same statements would had been said.Besides, Chrome isn’t Open-Source. You can’t see its source code, you just can use it freely. The “open-source version” is Chromium, which is almost unknown.

  14. Jeff Stewart says:

    It’s worth mentioning that at least one user out there switched from FF3 to Chrome, and gave up his extension-laden lifestyle to do it. Chrome is lightning fast, with sub-second startups regardless of the scenario (I rate startup time as probably the most important factor in choosing a browser). Its JavaScript engine is on top right now, and has saved me many minutes.I abandoned all the extensions I had in FF3 for Chrome because it’s faster to start and faster to browse. I use FF3 for Firebug now and stripped away most extensions in an effort to increase its performance, but beyond I’ve simply grown too impatient to wait on it, and am a regular Chrome user (on the beta channel).Quick test: starting Firefox 3.0.7 on my AMD Opteron 250 (2.41GHz, 2-processor) after a reboot took about 5-6 seconds. Subsequent startups took 1-3 seconds. Installed extensions are Firebug 1.3.3, S3 Firefox Organizer 0.4.6, and the Microsoft .NET Framework Assistant 1.0.I don’t know what Firefox’s perceived slowness can be attributed to; I imagine it’s extensions, but I am pretty conservative in that respect. At any rate whatever has changed in recent releases simply makes it take too long to launch, and I perceive its page loading performance to come in second to Chrome, too.The other 2 guys in my office are converts, too, and we all share the same complaints. *shrug*

  15. Ken Saunders says:

    @ Jeff Stewart (and others with the same opinions)”Quick test: starting Firefox 3.0.7 on my AMD Opteron 250 (2.41GHz, 2-processor) after a reboot took about 5-6 seconds. Subsequent startups took 1-3 seconds”Dude are you kidding?Do you mean that Chrome took that long to start up or Firefox?My enabled extensions fluctuates daily but on average, there are always at least 70 enabled and Firefox takes under 30 seconds to start.And this whole start up time with browsers is just plain bulls**t and whining anyways.Lets be real.What is the most common and popular thing that people do with a PC?They go online to use and browse the Internet. And for many, starting their browser is the first application opened after starting up their OS which in Windows takes what? 5 or more minutes?So 10, 20, even 30 seconds is worth bitching about?I just don’t get it.For me, once Firefox is open, it stays up until I shut down my PC and I suspect that is the case for most people regardless of their choice of browser.I’m not an idiot, I’m well informed, I’ve been using computers since the early 80’s when I got a TRS-80 MC-10 Micro Color Computer, I’ve been using the Internet consistently since 1998, I’ve tested thousands of applications of all kinds and so I’d hate to think that at this point in time that I wouldn’t be able to recognize and choose the best overall software of its kind and in this case, it’s Firefox. Add-ons or not, just checking email and Facebook or whatever, Firefox is the best browser that I’ve ever used and I have tried Chrome, Opera, Avant and others.And for the record yes, extensions will affect startup time. I just created a new Firefox profile and it took 5 seconds to fully load.If you have the need to shave off seconds off of your life to load a sub-par browser, then perhaps Chrome is for you after all, but I don’t mind waiting a few more seconds than you to use the best and most complete.I’ve had farts that have lasted longer than it takes Firefox to load. But I suppose for some reading this, I should probably change my shorts after that sort of length of time (or burn them).

  16. Anonymous says:

    Here, here! Firefox isn’t becoming more bloated, it’s becoming easier to use than ever. And faster!

  17. mpt says:

    “Mozilla is big because your needs are big. Your needs are big because the Internet is big. There are lots of small, lean web browsers out there that, incidentally, do almost nothing useful.”— Jamie Zawinski, 1998

  18. RNiK says:

    Great post and great review!I too think Firefox deserves more respect and less “insane-browser-prophecies”.

  19. David Tenser says:

    “Chrome is lightning fast, with sub-second startups regardless of the scenario (I rate startup time as probably the most important factor in choosing a browser).”This is something I simply don’t understand, although I have seen similar statements before.How can the time it takes to start a browser possibly be the most important factor in choosing a browser? How much time do you spend on _starting_ a browser vs actually _using_ it? Even if you just spend ten minutes per day actually surfing the web, your time spent on the web will be orders of magnitudes longer than the time your browser spent launching. Saying that the launch speed of a browser is the most important factor is just plain wrong.Yet, it seems to have a pretty massive psychological effect — it “feels” a lot faster.

  20. Jeff Stewart says:

    Startup time is what I feel most. I don’t do enough surfing to care about page rendering speed and I consider JavaScript performance a solved problem. But I think having to thrash the hard drive for 5-6 seconds to start a browser is unforgiveable. I’m kind of an ass about it.Why not leave my browser open? Bad habits, I guess. I got in the habit years ago of closing my web browser when I’m not using it, just like I close Windows Explorer or the command prompt when I’m done manipulating a file. I don’t need it around anymore and it’s really not a sure thing that I’ll come right back to it. I like things tidy, I don’t know. IE6 probably started that trend; its memory leaks required that I regularly “flush” it. Firefox had that problem for a while, too, especially during heady Firebug sessions (blame Firefox, blame Firebug, whatever).Anyway, the nature of my work has me switching tasks very frequently. And most of the computers I work on aren’t beefcakes; in fact a lot of them are virtual or remote machines that I tune into at unpredictable intervals. This, I suppose, reinforced the habit of eradicating applications and freeing resources I’m no longer using.Kind of an ass about it.So whatever I need to do at any given moment needs to happen quickly, ’cause I’m usually eager to move on to the next thing and put the current task behind me. Startup time really is what I feel most when using a browser.When when it comes to usability and performance, I’m in the “it’s as usable and performant as it feels, not as it benchmarks” school of thought. *shrug*Plus, when you see how fast a browser can start, it’s maddening to see other browsers fail to do the same. Add seconds of hard drive thrashing on top of that and it makes this techie a sad panda.

  21. Turk says:

    I was a die-hard FF person, but after FF3, I have given up. I wen back to FF2 for a few months waiting for the fix to come. After being unable to play Netflix in a down version, I upgraded back up to FF3. Basically, FF starts up, but if I try to access my toolbar, favorites etc, it is frozen. I had just as many bookmarks and live bookmarks as before.. Why won’t someone at FF fix this? I tried a bunch of the fixes listed by others on the internet, and none have helped. Tonight I downloaded Chrome and IE8. I am sad to be saying goodbye to Firefox.

  22. Brian says:

    Just wait until 3.5 is released. The speed will blow your mind. 🙂

  23. Anonymous says:

    Yes… loading time and memory consumption are really important for sure, you got a point here. But if we speak about java script performance… _unfortunately_, I will have to point that out: it with both FF and Chrome, and see what happens… really sorry.

  24. Anonymous says:

    Firefox 2 went like greased lightning on my system (WinXP 1.66GHz core duo), but Firefox 3.0.8 is slow as hell, and likes to crash lots.

  25. Anonymous says:

    My enabled extensions fluctuates daily but on average, there are always at least 70 enabled and Firefox takes under 30 seconds to start.So 10, 20, even 30 seconds is worth bitching about?30 seconds?On my laptop Vista takes only 10 seconds more to load, and here the fanboys still refuse to admit that Firefox is bloated to kingdom come.Amazing.

  26. Michael says:

    @ Kevin:"And if Mozilla introduces a feature in a Firefox beta, then all the people who don't beta test will not have a chance to give feedback."It stands to reason that those who actually cared about giving feedback would be participating in the beta.

  27. Anonymous says:

    First Off this author apparently knows nothing about "memory" addressing since "all" operation work in memory and if the program does not flush the memory area it was located in, it will cause memory leaks (which FF does now)Most programmers today are not worth the money it takes to train them (not their fault really more the fault of the high order programming languages that have bloated to an enormous level with far too much automation and not enough concentration on compiler issues)I use Opera myself since 2007 and stopped any FF operations because "IT HAS" gotten as bloated at the IE it was supposed to replace.. any idiot that does programming knows that anytime you "integrate" anything into an original piece of code, it "adds" to the code length, and since the codes run through a "newer" compiler that also has new code added to it, it just makes things "worse" because this entire length of code "HAS" to be ran in memory once compiles into machine code ergo "bloat"Just because you have more memory DOES NOT mean that you have more speed if the buss (bandwidth) of the overall CPU operational memory "internally" is being stretched too thin by the OS and other related so called "necessary" features to compete for cycles..If a CPU uses more then 10% of its capacity in front end operations, it leaves very little room for the back-end operations that keep the whole damn thing stable.. Any coder worth anything understands that the "footprint" of the code they are trying to make needs to always "remain small" and use modules (add ons) to accomplish secondary tasks.. and if it can be done with less overhead "DO IT"…The old words of KISS (keep it simple STUPID!) is what you should always live by in coding.. apparently too many hands in the pie, and not enough application of intelligence has caused FF to become reliable no longer as far as I am concerned..One last thing.. I too am a "technology whore" meaning that if the current browser I am using begins to get too bloated "I will" change to another that is less overhead, reliable for browsing (which is all a browser should do) and move on until I am arm twisted to actually design my own (lazy like others but at least I can admit it)..James

  28. Andy says:

    Firefox regularly consumes up to a gigabyte of RAM on my machine. If I restart it with the exact same tabs it will typically take only 400-500 megs.

    That looks like a memory leak to me, but what justification can Firefox give for needing 1 GIGABYTE of ram to render 10 or so tabs?

    Before you ask – I only have a few plugins – Firebug, Google Toolbar, and Accuweather.

    Sorry, as loyal as I have been to Firefox, I’m really looking for a lightweight and quick browser.

  29. Sharon says:

    I’m on a Mac and was a diehard Firefox fan but as the day went on, it took a gig of RAM and really slowed down. I’m using Google Toolbar, Web Developer and Firebug. I got tired of having to restart Firefox when it was ridiculously slow so I’ve gone back to Safari which is using only 1.5 MB of RAM. Now I only use Firefox for Web Developer or Firebug. Such a shame. I miss it and hope for a better version soon.