This guide explains the role of the browscap.ini file, which is used by PHP to identify certain characteristics of a web browser (name, version, operating system, and capabilities) based on its HTTP User-Agent header.

Using with the get_browser() function

The native PHP get_browser() function requires access to an up-to-date browscap.ini file in order to identify the characteristics of the browser that made the request.

On Infomaniak Web Hosting, this file is generally available at the following location:

/opt/php/lib/php/browscap.ini

If necessary, you can check its content using the following script:

<?php
header('Content-Type: text/plain');

$file = '/opt/php/lib/php/browscap.ini';

if (file_exists($file)) {
    echo file_get_contents($file);
} else {
    echo 'File not found.';
}

Due to its size and the cost of loading it, using browscap.ini can impact the performance of applications that rely on get_browser().

Recommended alternatives

For new projects, it is generally preferable to use solutions that are better suited to current web development practices:

• PHP libraries installed with Composer, such as matomo/device-detector or whichbrowser/parser, which offer regularly updated and more comprehensive browser and device detection.
• User-Agent Client Hints (UA-CH), when supported by the browser, to obtain structured information via the mechanisms provided by current HTTP standards.
• Feature Detection, by directly checking the availability of a feature (e.g., in JavaScript or with the CSS rule @supports) rather than inferring behavior based on the browser used.