Internet Explorer Testing Done Right
Here is the deal: you gotta test in IE. You don’t have to use it, you don’t have to like it, but you have to test in it. But which version do you test in? A normal windows configuration only allows a single installation of Internet Explorer. So if you are the good little downloader that Microsoft wants you to be, you are running IE 7. The problem is that IE 7 isn’t nearly as awful as the previous versions, so it doesn’t make an ideal candidate for a testing environment. The more bugs you find and fix, the better.
In my opinion, if you have to choose, do your testing in IE 6. IE 5.x is a dying fast and it shares many of it’s oddities and bugs with IE 6.
But I’m on a Mac! Good for you, me too, but that doesn’t skirt our responsibility to do serious IE testing. If you have an Intel Mac, you are in luck. I whole-heartedly suggest getting yourself a copy of Parallels. Parallels allows you to run Windows right from within OS X without rebooting. I have chosen Parallels as a sponsor for this blog for this very reason.
Here is the good news: you don’t have to pick a version, you can test in all versions of IE! Check out the Multiple IE Installer. This software allows you to install all kinds of versions of Internet Explorer for testing.

Now that’s Internet Explorer testing! They do have a warning up saying that some version of IE running under this software are subject to random crashing. Not great, but really a small price to pay for such a great tool.
Thanks to CSSVault for making me aware of this.















1
A word of caution about Multiple IE, it doesn’t always render pages correctly. We had used this in the shop but found many problems (flash not working correctly, styles ignored or altered, etc).
Simple solution: If you have XP don’t upgrade to Vista. XP has IE6 installed as it’s default. If you want to switch between 6 & 7 it’s a simple matter of installing/uninstalling the IE7 upgrade. The few minutes this takes is worth it.
Comment by John Schires — November 7, 2007 @ 7:14 am
2
Thanks for the cautionary tip, and the suggestion John!
That is a great point about switching back and forth between IE 6 and 7. It doesn’t take as long as you might think, because simply uninstalling IE 7 will leave IE 6 behind.
Comment by Chris Coyier — November 7, 2007 @ 7:19 am
3
Conditional comments won’t work as expected when using Multiple IE. They will always default to the most current version of IE you are running under the multiple install. Meaning… if you run IE6 and IE7 (under the Multiple IE) and you are trying to use conditional comments to filter styles just for IE6, the conditional comments will not work correctly.
Comment by chipgrafx — November 7, 2007 @ 9:57 am
4
Re the conditional comments problem, they have a note about that on Multiple IE’s homepage:
I’ve never had a problem with conditional comments after following these instructions.
Also, Parallels is good, but I’ve had more luck with VMware Fusion. In my experience it out-performs Parallels, and allows my Macbook Pro to run plenty of other programs at the same time.
Comment by Dan — November 7, 2007 @ 11:04 am
5
Thanks for noticing that fix Dan!
Also, I’ve heard great things about VMware Fusion. My choice of Parallels was just because that was the first one I tried and it works and it works well. I’d like to try out VMware someday if the situation arises, but in the meantime I still strongly endorse Parallels =)
Comment by Chris Coyier — November 7, 2007 @ 2:34 pm
6
I personal would just use the Multiple IE tool bar and just keep either IE6 or 7. Installing the others is pointless…
However if you have separate computers (most web geeks do), have both full proper versions.
Comment by Jermayn Parker — November 7, 2007 @ 8:47 pm
7
I agree. VM ware fusion is really great. I have Vista on bootcamp (which can be run via VMware too) and XP, but I do all of my IE testing in XP (Vmware), where I run a standalone version of IE6 (make sure to adjust your registry to enable conditional comments) and the normal version of IE7 (I don’t test lower than IE6 anymore). Good article Chris!
Comment by Glen — November 13, 2007 @ 7:09 pm