Detect and Redirect Mobile Users in PHP

Question

I'm curious of a simple, common, universal way to detect a mobile user so I can redirect them to a mobile directory...

What is best for this: Javascript - CSS - PHP?

I think for my purposes if I can detect screen size or mobile browser agent - that would be good enough for what I need right now.

Answer 1

To your question, there are two problems:
1) Looking for a browser signature is a needle/haystack proposition, and the haystack is enormous, and it gets bigger every time a new phone/tablet model comes out;
2) Screen size used to be a good indicator, but as I feared when people first started using screen resolution as the main indicator, the screens on mobile devices have become progressively more and more capable. Some of them are better than many desktops I've seen.