PHP-FPM

PHP-FPM is a helper on your hostingWeb hosting is the service that keeps your website's files on a computer that is always online, so visitors can open your site at any time. that runs your site’s PHPPHP is a programming language that builds your web pages on the computer that hosts your site, just before they reach the visitor. WordPress runs on it. code as a separate job and hands the finished page back to the program that answers visitors. You rarely see it, but it is one of the parts that sit between a visitor and your pages, and many hosts run their websites this way.

What is PHP-FPM?

The name stands for FastCGI Process Manager. Many hosts run websites this way, with nginx or Apache in front.

A web server such as nginx cannot run PHP code itself. It passes the request to PHP and waits for the answer. With PHP-FPM, PHP runs as its own service with a pool of worker processes. The web server sends a request to a free worker, the worker runs the PHP code and sends the page back, and the worker is ready for the next request.

Because PHP-FPM is a separate service, you can give each site its own pool, with its own user, its own limits and sometimes its own PHP versionA PHP version is a numbered edition of PHP, like 8.3. Each edition is looked after for a limited time, then gets security fixes only, then nothing.. That keeps sites on the same server apart from each other and makes it possible to tune the settings per site, such as the number of workers or the memory_limitmemory_limit is a PHP setting that decides how much memory the code behind one page may use. If it needs more, it stops with an error..

How it differs from mod_php

The older approach, mod_phpmod_php is an older way of running PHP, in which PHP is built into Apache, the program that answers visitors, instead of running as a separate helper., loads PHP into every Apache process. PHP-FPM keeps the two apart. For you this means that updating or restarting PHP does not require restarting the web server.

PHP-FPM and your WordPress site

For a WordPressWordPress is free software for building and editing a website in your browser. It is written in PHP, so it builds each page when someone visits. site, PHP-FPM is mostly invisible. You notice it when a page runs slowly because all workers are busy, when a fatal error shows up in the error logAn error log is a file where your website's software writes down what went wrong, with the time and place. It is the first thing to check when a site breaks., or when a setting changed in php.iniphp.ini is the settings file for PHP on your hosting. It sets limits, such as how much memory a script may use, how big an upload may be and if errors show. does not seem to work. In the last case the usual reason is that PHP-FPM was not reloaded.

During a PHP update the service matters in another way. On a server with several PHP versions, each version runs its own PHP-FPM service. Switching a site to another version means pointing its web server configuration at the other service. Hosting panels hide this behind a dropdown.

How to check what you run

In your hosting panel you will usually see the handler next to the PHP version, with a name such as PHP-FPM, FastCGI or Apache module. A phpinfo page shows the same under “Server API”, for example FPM/FastCGI.

On the vulnerabilities of October 21, 2026, php.net names PHP-FPM, Apache with mod_php, php-cgi, FrankenPHP and LiteSpeed among the installations serving web requests that are at risk. So the handler does not decide whether you need the update. The version does. The free PHP exposure check helps you see what your site shows from outside.

When to act

Look at PHP-FPM when you update PHP, when your site hits worker or memory limits, or when settings do not seem to apply. For the update itself, our PHP upgrade service covers the service configuration, the test and the switch, so your site does not depend on you knowing which service handles which version.