PHP – Get Firefox Browser Version

The post shows you how to get the version of Firefox browser using PHP.

To do this, we simply look at User-Agent data ($_SERVER['HTTP_USER_AGENT']) to determine whether the visitors are using Firefox browser and then extract Firefox version from it.


Here is the code:


function getFirefoxVersion()
    $version = null;

    $userAgent = strtolower($_SERVER['HTTP_USER_AGENT']);
    if (strrpos($userAgent, 'firefox') !== false) {
        preg_match('/firefox\/([0-9]+\.*[0-9]*)/', $userAgent, $matches);
        if (!empty($matches)) {
            $version = $matches[1];

    return $version;

The above function returns the version if the browser is Firefox and we extract the version in the User-Agent successfully, null if the browser is not Firefox.


Use the function:

// Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:60.0) Gecko/20100101 Firefox/60.0
$firefoxVersion = getFirefoxVersion();
echo $firefoxVersion;