This Just In: Firefox is Still Slow
Mozilla released the first beta of Firefox 4 yesterday. In addition to offering a spiffy, new interface and a whole host of new features, including enhanced HTML5 and WebM video support, the latest version should be faster. As there have been a few new browser releases recently, with Opera, Chrome and Safari all making great leaps forward, I though it was time to do a comprehensive head-to-head test to see how the new Firefox stacks up against them.
Rather than using my usual testing suite, WebKit’s SunSpider, for this shootout I used Mozilla’s Dromaeo testing suite. Dromaeo takes a lot longer to run — around 15 minutes or so — but it’s also much more comprehensive than SunSpider (it actually incorporates tests from Sunspider and also from Google’s V8 benchmark suite). For comparison, I also used the Peacekeeper tests, another comprehensive browser performance testing suite. Testing was done on my 2.53 GHz Intel Core 2 Duo MacBook Pro; only the major Mac browsers were tested.
Dromaeo
The chart shows the results of the Dromaeo test. A higher score (more runs per second) is better.
Peacekeeper
This chart shows the results of the Peacekeeper test. A higher score is better.
Conclusions
While there is some disparity between the results — it’s surprising that Opera 10.6 does very well on the Peacekeeper test (and in my previous SunSpider tests) but not so well on Dromaeo — it’s clear that although the beta of Firefox 4 shows a definite improvement, it’s still lagging behind the other browsers, particularly Chrome, which was the fastest on both tests. Hopefully that’s something the Mozilla developers will work on as they work towards a final release of Firefox 4, which is due by the end of the year. However, given the rapid release cycles of the other browser vendors, will Mozilla be able to keep up? Firefox still has a few aces up its sleeve — a giant extension ecosystem, an enormous user base and some innovative new features, like in-browser contacts management — but on raw speed it’s still losing out to its main competitors.
If you’d like to try Firefox 4, you can download it here. As with all pre-release software, there may still be some gremlins to iron out.
Let us know what you think of the new Firefox 4 beta in the comments.
Related GigaOM Pro content (sub. req.): What Does the Future Hold For Browsers?


For what it’s worth, they haven’t landed their major JS engine overhaul just yet. You can follow their progress on http://www.arewefastyet.com/
This must be like their 3rd attempt to overhaul the JS engine since Chrome came out. Opera seems to keep up with V8 with their new JS engine, Firefox so far couldn’t.
I don’t follow – Opera has a new JS engine (Carakan), while Firefox is still using the one-year-old Tracemonkey, which itself had flaws.
Since Chrome was released, there have been 2 versions of Firefox (3.5 & 3.6) released, both of which use Tracemonkey. So, it’s not their 3rd overhaul attempt :-)
Mozilla is working on comprehensive browser features, expanding the open web, and ensuring users get the best possible experience out of the web through their browsers.
Pure JavaScript speed is not the only factor for web browser performance and overall usefulness.
At the end of the day I think Mozilla works harder to make Firefox the best overall browser for users. Google throws a lot of weight behind speed and simplicity, but Mozilla is about more than that.
Obviously speed is a big deal though and the race is on. As someone else pointed out, the new JS engine has not landed in FF 4 Betas yet. We’ll see it soon enough. And to be sure, Mozilla is working very hard to making Firefox as fast as possible.
I’m also quite certain that if, for example, Firefox 4 Final was the fastest browser on the planet – inevitably the next nightly of Chromium or Opera would edge it out. It’s going to be an indefinite battle for supremacy.
“It’s going to be an indefinite battle for supremacy.” I agree, and it’s great news for us users. Thanks for your comment.
♥ I have tried my hands on latest regular versions Firefox , Chrome , Safari & Opera !
♥ I don’t think user gives shit to just one feature set of Speed & Simplicity ( except some geeky , nerdy types people — me included ) !!
♥ Firefox delivers better with so many add-ons installed.
♥ It’s about overall experience !
Well, to be honest. I find FireFox 3.6.6 faster than Safari 5. Plus, I can’t really live without AdBlock Plus. The Safari version is not as robust for some reason.
The only real complaint I have about FF is that it doesn’t “resize to fit” the window when you click on the green window size widget. It still maximizes as if it was running in Windows OS. I really hope they fix this.
Mozilla specifically stated that Javascript performance improvements are not yet in the Beta, but the Dromeo benchmark solely tests Javascript performance. That’s unfair.
http://www.mozilla.com/en-US/firefox/beta/features/
http://hacks.mozilla.org/2010/07/firefox-4-beta-1-is-here-whats-in-it-for-web-developers/
More appropriate benchmarks would focus on page loading, as the blog post above does tout improvements on that.
Thanks for the comment, Luigi. When Mozilla updates Firefox with its new JS engine, I will certainly rerun the tests.
I am shocked !!
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Not only that. But Firefox is the only browser that can’t do 100/100 on Acid 3, and also is the last one on the HTLM5 test (http://html5test.com/), nor can show h264 HTML 5 video.
So… worse browser now. Of course not including IE that fortunately doesn’t run on my Mac ;)
I missed the part where using h264 was part of the HTML5 spec. They support WebM, which Safari doesn’t.
Additionally, are you sure you ran Firefox 4 against the HTML 5 test? Just by looking at the page (No FF4 at work), I think FF4 would be a shoe-in for the top spot.
A follow-up to my previous comment: FF4 looks like it’ll beat it’s Webkit competitors with it’s HTML5 support: http://caniuse.com/#cats=HTML5&statuses=rec,pr,cr,wd,ietf
Additionally, what do you gain from having a browser that gets a full 100%, other than the fact that you know it gets 100%? I’m not saying it isn’t a noble aspiration, but does it make a more usable browser?
Speed is always an issue, but for many of us who use Firefox, its advantage is that it’s really become more than just a browser. With the judicious addition of some well-designed add-ons, it can be a tool for managing multiple email accounts, testing and troubleshooting web pages, managing passwords, synchronizing data, and much more.
Indeed, Charlie — speed is not everything, features and stability are probably more important for most users.
Chrome does have a reasonably healthy extension ecosystem now though.
Bullshit! Speed is everything for the present culture.It is exactly like in daily traffic. You start hating slackers that wont move fast enough! Firefox doesnt give a shit about users experience, thats why you excuse with: speed isnt everything. Addons all browsers have or will have.
At least there is some kind of speed increase. I’ll still continue using Chrome though. Fast, clean and simple.
I think it’s important that Mozilla starts understanding that speed and simplicity is becoming the winner in this. Firefox might have gotten a little faster now, but Chrome, Safari, IE and Opera will probably continue leaping forward too. I’ve introduced Chrome to a lot of Firefox users and all of them has been delightfully surprised at how good it is.
Needless to say, none of them went back to Firefox after a day or two getting used to Chrome.
These benchmarks are useless to me. I’m on a crappy old 1.8GHz Celeron and you know what browser I use? Firefox 2.x. You know why? Post-1.0, Chrome has been getting slower and slower and slower on it. Yet your test shows Chrome should be like lightning in a bottle.
I know how you feel, Mike. I had an 800mhz PIII running GNU + Linux and Chromium was like molasses. It loaded pages promptly but scrolling through Gmail and buzz was excruciating. Firefox was much faster.
Additionally, when are we going to get some GPU accelerated javascript engines? What about firefox’s D2D acceleration, does that change benchmarks at all?
I was reading some stuff on the Unofficial Firefox forum and like many people said their javacript trump card isn’t yet in the beta. I am not sure the about technical details but some posters have claimed(for whatever thats worth) that Jagermonkey + tracemonkey has the potential of at least being in rough parity with V8 and maybe surpassing it.
The main attraction of the Firefox 4.0 beta is the GPU acceleration though. The difference is very noticeable especially the improvement in scrolling.
In addition to my comment above, one of the coders of jagermonkey notes at http://arewefastyet.com/
“note for the worried: the tracer JIT (orange) and method JIT (black) are not yet integrated.
once integrated, the merged branch will be faster than either branch individually.
they are complementary.”