Beside that most of the responses of $_SERVER[‘HTTP_USER_AGENT’] may return, it appears that this is the most reliable way to track down a user agent with PHP. It is weird that most of the clients, i.e. Safari and Chrome will return something with Mozilla in it’s strings, but however it’s enough to track the “chrome” or “safari” sub strings.

All the examples bellow are from Mac OS X:

Firefox 3.6:

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6

Note: there are both Mozilla and Firefox sub strings!

Safari 4:

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_8; bg-bg) AppleWebKit/531.21.8 (KHTML, like Gecko) Version/4.0.4 Safari/531.21.10

Chrome:

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_8; en-US) AppleWebKit/532.9 (KHTML, like Gecko) Chrome/5.0.307.11 Safari/532.9

Note: Here they are Mozilla, Chorme and Safari!!!

Opera:

Opera/9.80 (Macintosh; Intel Mac OS X; U; en) Presto/2.2.15 Version/10.10

The day of mobile

Nowadays it’s normal to make a site with the presumption it will be visible from mobile. The war between Nexus One from Google and iPhone from Apple is just beginning and with all those devices with wide screens everything’s becoming more complicated.

User agent strings from Nexus One and iPhone

Both are weird, but both contain the keyword – “mobile” and that may help you make a check with something like this PHP snippet: