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I have a database of user agents that I need extract all of the unique browsers from in SQL. The field is like...

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv: Gecko/20100722 Firefox/3.6.8
Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; InfoPath.1; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022)
Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; GTB6; InfoPath.2; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; OfficeLiveConnector.1.3; OfficeLivePatch.0.0; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET CLR 1.1.4322)
Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)

I was wondering if anyone had done anything like this before or knew of a good resource online to assist with this.

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Keep in mind that in many cases it's trivial for the user to change the user agent on whatever browser / client they're using. – squillman Aug 26 '10 at 18:05
up vote 0 down vote accepted

It's called Browser Fingerprinting; there's a lot of info around the web. I don't have any great source offhand though. You need more than just the user-agent to get a good fingerprint, but it's a good start.

These tactics are great for data-mining trends and such; but don't work very well for actually personally identifying a computer. This site will even tell you how unique you're browser is.

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