Question

Every now and again I get asked to install something like this on a customer web server, or we’re asked if we support BrowserHawk (which we don’t).

I’m wondering if Modernizr is something I can point my customers at and tell them to use instead?

Answer 1

I’ve not used Browserhawk (in fact, I’d never heard of it until now), so please don’t take my opinion as infallible.

However, I do know about browsecap.ini, and having taken a few moments to read the Browserhawk website, I’m fairly certain it’s also a server-side browser detection tool.

If that’s the case, then the answer is ‘Yes’. Current best practice says to avoid using server-side browser detection, and to use client-side feature detection instead. And this is exactly what Modernizr does.

Feature detection allows you to do much finer-grained tuning of your site according to what the user’s browser is capable of, rather than simply blocking users who have (or don’t have) a particular browser. It also allows you to implement specific fall-back solutions for specific features, if required.

Detecting the user’s browser from the server-side is a problem because of the rapid pace of change in the browser market; you would need to be constantly updating your browser detection script to cope with new versions.

In addition, users of slightly more unusual browsers or browser shells may not be detected properly by a browser detection script, so they may have trouble with sites that use it, even though their browser should be capable of displaying the site. Also, some users may not provide the user-agent string required to correctly detect their browser; it is blocked by some proxies, firewalls, etc, and some browsers also allow it to be modified, so it can be spoofed easily if a user wants to.

But having gone to lengths to promote feature detection over browser detection, I need to point out one exception to all of this, and that’s IE.

Older versions of IE have a lot of bugs. This is different to simply having missing features, because you can’t actively check for bugs so easily. If you’re having specific issues with IE bugs, then it is legitimate to do browser detection to avoid them. (feature detection is still valid if you’re only worried about what the browser supports, rather than actual bugs)

But even in this case, a tool such as browsercap.ini or Browserhawk is unnecessary. IE helpfully supports Conditional Comments which allows you to add specific code for IE without having to go out of your way to detect it.