I just read an interesting post from Microsoft’s Internet Explorer team on The IE7 User-Agent String. This statement in particular illustrates a problem not unfamiliar to Opera users:
There are a few remaining sites which fail to recognize IE7 because they are performing exact string matches to look for specific IE version strings. Those checks will need to be removed or updated to accommodate IE7.
Yes, you read that correctly: there are websites out there using bad browser sniffing code which will send the wrong code to Internet Explorer 7. In fact, they go on to say that they’ve released a tool which will let IE7 pretend to be IE6!
To enable you to workaround any remaining sites that block access to Internet Explorer 7, we developed the User Agent String Utility. The utility comes in the form of a small executable that opens an IE7 instance that sends the IE6 user agent string. It also provides a mechanism for you to report problem web sites to Microsoft so that we can follow up with the affected site owners.
I’ll admit to a certain amount of schadenfreude, but it also points up just how bad a strategy browser sniffing can be when done thoughtlessly: It effectively builds an expiration date into your website after which even the browser you designed it for will run into problems.
*This post originally appeared on Confessions of a Web Developer, my blog at the My Opera community.