So, Fire­fox 3.6 is finally here, and on aver­age it’s 20% faster than 3.5. It’s actu­ally a really notice­able improve­ment for both ren­der­ing and scrolling around pages; I’d say it’s more or less on a par with Safari on most pages. I hear from Win­dows using friends that it’s sim­il­arly quicker on that plat­form too, approach­ing the speed of Chrome, in places. All of which makes this a little odd.

I noticed, not long after the upgrade that my blog (this page, unless you’re read­ing a syn­dic­ated copy,) was scrolling really, really slowly in Fire­fox, which it had never done before I upgraded. I checked it in Safari to reas­sure myself that it wasn’t some­thing wrong with the site, and everything was fine; scrolling was smooth and respons­ive just like it has always been. I checked Fire­fox 3.5 on my mac­book; same thing. I dis­abled all my fire­fox addons and tried again on the desktop: still pain­fully slow. So I re-​​enabled some of them and star­ted mess­ing around with fire­bug, dis­abling vari­ous style ele­ments to see if I could fig­ure out where the slow­down was com­ing from.

It didn’t take me long to find the cul­prit: shad­ows. I try to avoid using images in my pages as much as pos­sible to improve page load speed, so I use box-​​shadows to give a bit of depth to the wid­get box-​​outs; they look even more flat and drab without them. I also find that a subtle text-​​shadow is a great way to increase text con­trast without mak­ing the page harder on the eyes, which is a big deal for any light-​​on-​​dark dis­play (at least until someone intro­duces a decent super-​​light web­safe font,) so I make heavy use of that too. None of this has ever had any notice­able per­form­ance impact before, but here we are; with the new, optim­ised, gecko engine it renders like arse.

I thought per­haps there was some­thing else about my CSS that was con­fus­ing the ren­der­ing engine — it’s hardly the most min­imal or eleg­ant set of style defin­i­tions in the world — so I knocked together this abuse of text-​​shadow to prove that it’s the prob­lem. As expec­ted, it renders fine in Safari and older Fire­foxes, but incred­ibly slowly in Fire­fox 3.6, so it’s def­in­itely some­thing to do with the new browser.

Next check was to see if it affects FF3.6 on other plat­forms, so I fired up my Win­tendo, upgraded Fire­fox and tried the page. No slow­down. I don’t know how rep­res­ent­at­ive that is though; that box is a quad-​​core 3GHz Nehalem with 6GB of RAM and a GTX295 in it; it’s got about twice the graph­ics oomph of my Mac (which is a 3GHz Core2 Duo with an 8800GS), and I don’t have a slower win­dows box to test on. So this is a bit incon­clus­ive; I can’t really det­mine whether the issue is con­fined to the Mac ver­sion of Fire­fox, or to Fire­fox on machines that can’t run Crysis at 60fps. But, hon­estly, I don’t think it matters.

Long story short; my site renders really slowly on the latest, greatest ver­sion of Fire­fox, which is an issue. I make no bones about the fact that I don’t give a monkey’s how it renders in IE, but I do like to make sure it gives a good exper­i­ence in decent browsers, which by my defin­i­tion means any­thing web­kit or gecko based. Fire­fox is by far the most pop­u­lar browser in that cat­egory, so I can’t just ignore this. The ques­tion is what to do?

I can sit around and hope that 3.61 fixes the prob­lem, but that is basic­ally just ignor­ing it, tak­ing no respons­ib­il­ity, and means that my site sucks until someone else fixes their browser, which might never happen.

Or I can reskin the whole site such that it looks OK (or at least as OK as it looks now) without rely­ing on shad­ows. The prob­lem is, I’m not a web designer, so that’ll take me ages, and I only just got the place look­ing how I want with this design. It’ll also, inev­it­ably, mean mov­ing back towards the bad old way of doing things, using back­ground PNGs to try to give the site any sense depth or char­ac­ter, and I really don’t want to do that; I want to be able to use stylesheets to define the style of my page, not rely on image-​​based work­arounds. Admit­ting that I need those work­arounds feels like giv­ing up. Maybe the state of browser tech­no­logy just isn’t up to that out­look yet.

Basic­ally, I see no entirely sat­is­fact­ory way out of this situ­ation; I’m just going to have to decide which solu­tion is the least unsat­is­fact­ory. I’m going to have to give it some thought.

So, Down­load Day 2008 is done, and they man­aged slightly over eight mil­lion down­loads. That’s got to be enough to get them the record. I hope you all contributed.

Of course, there cur­rently is no record for the most down­loaded piece of soft­ware in a single day, so it’s not a hard one to set. The ques­tion is: how long will it stand? And will it be Fire­fox 4 that breaks it?

At some point in the next day or so Fire­fox 3 will be released, and they’re aim­ing to estab­lish the record for the most down­loaded piece of soft­ware within a single day of release.

Fire­fox 3 is a great browser; a notice­able improve­ment over ver­sion 2, and much bet­ter than any of Microsoft’s efforts (and I’m speak­ing as a web-​​user here, not just as an open-​​source advoc­ate.) Even if you can’t see what all the fuss is about I’d encour­age you to find out, and if you do it sooner rather than later, you’ll be part of a set­ting a world record.

So head over to their world record attempt site and grab the browser if it’s up by the time you read this, or pledge to do so if it’s not. It’ll be worth the few minutes of your time it’ll take.

Edit: It’s now live, you can go and grab it any time you like, and if you do so before 6PM BST tomor­row (18^th June 2008) it’ll count for the record attempt.

Edit 2008÷06÷18 12:00: Three quar­ters of the way through, and just shy of six-​​million down­loads. It’s a great fig­ure already, and there’s still six hours to go. If you haven’t got hold of it yet, you haven’t missed the chance, and the serv­ers all seem to be cop­ing much bet­ter now.