Ok, this serves as a good example of how not to do UA sniffing.

User Agent sniffing is a process of discovering the User Agent (browser in most cases) of the client visiting your page. Historically designers and developers used UA snifing to determine what hacks they would implement to ensure consistency across browsers and platforms.

UA sniffing is also used for many so-called ‘black-hat’ SEO techniques. You sniff for Google’s UA, which is unique, or the IP addresses of Google’s spiders and serve up a ‘special’ version of your page for the GoogleBot. In search engine terms this is known as ‘cloaking’, and is possibly the worst offence you can commit. (If you get caught :mrgreen:)

When User Agent Sniffing Goes Wrong

In this Blind People Can’t Eat Chcolate I alluded to some issues with the new Lily O’Briens Chcoolate website.

Well screen readers weren’t the only user agent that had difficulties with the new website:

That’s what the server was returning to the GoogleBot UA. Absolutely one of the worst cases of arsing up UA sniffing I have ever seen.

Thankfully they seem to have fixed the issue. (Hello Magico :grin:)

Can A Short-lived Mistake Cost Dearly?

I’m not sure how long the site was returning that response to GoogleBot. It was a site-wide result so if it does get picked up it will likely be site-wide. Michele already alluded to the changed page URLs, but if they were very unlucky, and GoogleBot tried to crawl the site while the server was parsing that crappy message, the site may find all of their pages quickly entering supplemental hell.

I hope they weren’t this unlucky – getting out of the supps can be a nightmare of horrible proportions.

Oh, and a hat-tip to eagle-eyed David Doran