Firefox 4 is Fast

I’ve been running the Firefox 4 betas, and I’ve been trying to keep an eye on speed, as that seems to be one of the main reasons cited for switching to Google Chrome by Firefox users I talked to.


Now, don’t get me wrong, Chrome is fast, that much is true, but I think what a lot of people forget about is the cruft. For many users, it could be a few years since they’ve done a fresh install of Firefox. I mean fresh as in “starting with a new profile” so that all your old preferences, add-ons, plug-ins, bookmarks, and other bits weren’t there.

Right now if you download Google Chrome for the first time, and launch it, there is no cruft. It launches fast. If you’ve been upgrading Firefox over the years and not starting fresh with a new profile… well, there’s cruft.

Here’s what I did, and you can try it at home. Create a new user account (if you’re running Mac OS X, just log into the “Guest Account” that wipes itself after every logout) and launch the Firefox 4 beta. For fun launch Google Chome as well. Both will be cruft-free as they won’t have any previous preferences/profile to worry about, and will be starting fresh.

In my tests, Firefox 4 launched pretty damn fast. If Chrome launches faster, it’s probably by such a small amount that most people could never tell.

Now jump back and forth between Firefox and Chrome and load various pages. Again, don’t use any magical timers, just experience it, and see if you think they are pretty close. They look pretty close to me.

As I’ve mentioned, speed isn’t everything, but it’s nice to see the Mozilla folks stepping up their game and realizing that speed is important to a lot of people. I’ve also read some comments about finding ways to “cleanse” old profile data, to help the folks who have been using the same Firefox profile for years and years, hoping for a bit better performance.

Disclaimer: This is not scientific! I did not run any benchmarks, I didn’t test Javascript engines, or anything too crazy or stressful, I just compared the experience of launching/browsing using completely fresh installs of (the latest beta of) Mozilla Firefox and Google Chrome. I’d love to hear some comments from a Chrome convert willing to do the same tests.

7 replies on “Firefox 4 is Fast”

Although not the same kind of speed as startup speed, javascript speed is another area where Mozilla is looking to improve with Firefox 4. It hasn’t been put into the beta builds quite yet, but should hopefully land soon. You can track the progress as well as compare to V8/Nitro here: (As you’ll see in the note at the bottom, they will be combining the tracing JIT with the method JIT before it’s completed, and they will be complementary)

Jordan, the Javascript engine in Firefox definitely has a way to go as far as speed. I mainly did this experiment as a result of people saying things like “Firefox takes forever to start up!” or “Chrome loads pages faster!”

I’m also probably not someone who uses super-heavy Javascript sites, so I’m not sure how useful my tests would be in that case.

I haven’t tried with the Fx4 betas yet, but on my machine (look ma, no science!), Firefox takes ~10x as long to load from a cold start. That is with approx the same number of extensions in each browser (I have more in Chrome than in Firefox).

I went to disable a few in Firefox to see if it would affect page load time but I would have had to restart my entire browser.

With that in mind, I haven’t yet compared the number of plugins, rather than extensions.

Phil, there is a definite difference in launch time between Firefox 3 and Firefox 4… and I’m assuming it’s even better if you can start with a “clean” profile as I did. Let me know if you get better results with the Firefox 4 beta.

Firefox 4 feels much faster so far, although at the expense of legible title text in tabs, which is a bit of a bummer. I went to give some feedback but got “Your comment contains swear words (titles).” ho hum.

This is b4. I don’t think it would be fair to use this version until I can read the titles of my open tabs – it would influence me too much, so I’ll wait for another version before passing judgement, but it *does* feel snappier so far.

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