Most developers would find and use a library rather than write their own parser. They pretty reliably extract the browser/version/platform/etc from the hundreds

Most developers would find and use a library rather than write their own parser. They pretty reliably extract the browser/version/platform/etc from the hundreds of thousands of UA strings you'll see in the wild. https://github.com/tobie/ua-parser https://github.com/tobie/ua-parser https://github.com/browscap/browscap https://github.com/browscap/browscap A user agent parser is built in to the PHP language as well. http://php.net/manual/en/function.get-browser.php http://php.net/manual/en/function.get-browser.php