What Is PHP? How It Runs on Your Server and How to Choose and Upgrade Your Version (2026)

What is PHP? The language that runs on the server, not on your computer, and how to choose its version — What is PHP? The language that runs on the server, not on your computer, and why its version matters even if you never write a line of it

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📅 Updated October 2026 The explanation draws on the official PHP manual (php.net) and its supported-versions page (read October 12, 2026), usage figures from W3Techs (October 12, 2026), recommendations from WordPress.org, and host limits from the help pages of Hostinger, Kinsta, IONOS and Pressable.

In your hosting panel you see a drop-down called "PHP version" with 8.2, 8.3, 8.4 and 8.5 in it. A "PHP update required" message appears in your WordPress dashboard. And support tells you your site went down because "the plugin does not support this version." So what is PHP? Why does it run on the server and not on your computer? And which version suits your site? This article explains the language from the ground up in plain terms, without asking you to write any code, then gives you practical steps to find your version and upgrade it safely.

The short version: PHP is a programming language that runs on the server to generate web pages on demand (WordPress and most content management systems are built on it), and only its HTML output reaches your browser. The thing you control most as a site owner is its version: versions past their end of support get no security updates, and WordPress.org today recommends PHP 8.3 or newer.

📋 Quick summary: PHP in one table

Item	In plain words
PHP	An open-source scripting language suited to web development, which can be embedded in HTML pages and is executed on the server
The name	A recursive acronym: PHP: Hypertext Preprocessor
Origin	Created by Rasmus Lerdorf in 1994, with its source code released to everyone in June 1995
Reach	69.7% of the websites whose server-side language is known, according to W3Techs on October 12, 2026
Supported versions	8.2 through 8.5 (8.2 and 8.3 with security fixes only), and everything earlier is out of support
WordPress recommendation	PHP 8.3 or newer; WordPress works with 7.4 and above, but those versions are out of support
With the server	The web server passes the request to PHP (often through PHP-FPM) and returns the output to the visitor

What is PHP? The definition and the roots

The official PHP manual defines it as a widely used open-source general-purpose scripting language that is especially suited to web development and can be embedded into HTML. Its name is a recursive acronym (PHP: Hypertext Preprocessor). The manual says the beauty of using it is that it is very simple for a newcomer and offers many advanced features for a professional programmer.

Where did it come from?

The history page of the manual tells how it succeeded a product called PHP/FI that Rasmus Lerdorf created in 1994. Its first form was a simple set of CGI programs written in C, which he first used to track visits to his online resume, and he called them "Personal Home Page Tools." He released the source code to everyone in June 1995, then rewrote it a few months later and deliberately made its syntax close to C so that people who knew C and Perl would find it easy. In other words, PHP began as a way to make a web page "live" instead of static.

Why does it run on the server? The difference from JavaScript

The official manual explains what sets PHP apart from a language that runs in the browser, such as JavaScript: its code is executed on the server and generates HTML that is sent to the client, so the visitor receives the result of the execution and has no idea what code produced it. Because of that, servers can even be configured to process HTML files through PHP, so a visitor cannot tell it is in use.

A simple example shows the idea. This is a line inside a page:


<p>Year: <?php echo date("Y"); ?></p>

When a visitor requests the page, the server runs the part between <?php and ?> and replaces it with the result, so the browser receives <p>Year: 2026</p> with no trace of the code. And if you open "view source" on any PHP site, you will see only HTML. That is what allows pages that change by visitor: their name, the products in their cart and the latest blog posts.

How does PHP reach your site's visitor? The journey of a request

The visitor requests a page. The request reaches the web server (Apache, Nginx or LiteSpeed).
The server passes the PHP request on. A server such as Nginx does not run PHP code itself; it sends it to a PHP service through FastCGI.
PHP runs the code. It reads from the database and assembles the theme and plugins into one page.
The output comes back. Ready HTML that the server sends to the browser.

The official manual describes PHP-FPM (FastCGI Process Manager) as an alternative implementation of FastCGI with extra features that are mainly useful for heavily loaded sites, including advanced process management, pools that run workers with different settings and a log for slow scripts. In some hosts' panels you will find a number of "PHP workers" in the plan specifications: this is the number of PHP requests that can run at the same time, so the more of them, the more requests your site can handle together. To understand the role the server plays, read What Is Web Hosting.

⚙️ Want a panel where you pick the PHP version with one click?
Hostinger: its help page says you choose from 8.2 to 8.5 under PHP Configuration, with 8.3 selected by default
☑️ See Hostinger plans

Where is PHP used? More than you expect

Content management systems: WordPress, Joomla, Drupal and WooCommerce are built with it.
Large sites: W3Techs lists Wikipedia and WordPress.org among the sites that use it.
Live site functions: login, forms, shopping carts, search and comments, everything that changes by visitor.
Maintenance tools: PHP can be run from the command line without a web server, for scheduled tasks, for example (the manual lists this as a second area of use).

W3Techs says that on October 12, 2026 PHP was used by 69.7% of the websites whose server-side language is known. Note the wording: it is a share of the sites whose language is known, not of all the sites on the internet.

PHP versions: what is supported and what has ended?

The supported versions page says each branch is fully supported for two years from its release (bug and security fixes), then for two more years for critical security fixes only, and then it reaches end of life (EOL) and is no longer supported. This is the state of the branches on October 12, 2026:

Branch	Released	Full support until	Security support until
8.5	November 20, 2025	December 31, 2027	December 31, 2029
8.4	November 21, 2024	December 31, 2026	December 31, 2028
8.3	November 23, 2023	Ended December 31, 2025	December 31, 2027
8.2	December 8, 2022	Ended December 31, 2024	December 31, 2026 (in under three months)
8.1	-	Out of support since December 31, 2025
8.0	-	Out of support since November 26, 2023
7.4 and earlier	-	Out of support (7.4 on November 28, 2022, 7.0 on January 10, 2019 and 5.6 on December 31, 2018)

At the time of writing, the php.net page shows version 8.6.0 (release candidate RC3) available for testing, and test releases are not for a live site.

What do people actually do?

According to W3Techs (October 12, 2026): version 8 is at 64.7% of the sites that use PHP, version 7 at 27.5%, version 5 at 7.8% and version 4 at 0.1%. Versions 7, 5 and 4 are all out of support at php.net, and "version 8" also includes 8.0 and 8.1, which have ended too. WordPress recommends PHP 8.3 or newer on its requirements page, and says it works with 7.4 and above but that those versions are out of support and may expose your site to vulnerabilities. Its PHP update page adds that a newer version is faster and more secure.

⚠️ Do not upgrade the version with one click and no preparation: WordPress.org says an upgrade should not cause a problem but does not guarantee that, because your theme or plugins may not work on the new version, and it advises a backup, updating everything and testing compatibility first (see the steps below).

What does your host decide about PHP?

The host decides which versions are available and the runtime settings. The language's defaults, according to the official manual, are modest: memory_limit defaults to 128M, max_execution_time to 30 seconds, post_max_size to 8M and upload_max_filesize to 2M. Hosts usually raise them in their plans, and this is what Hostinger shows in its shared hosting limits table (read October 12, 2026):

PHP limit (Hostinger)	Single	Premium	Unlimited
PHP workers	20	40	60
PHP memory limit	1024MB	1536MB	2048MB
Maximum execution time	360 seconds	360 seconds	360 seconds
Maximum upload file size	1024MB	1536MB	2048MB

Hosts differ in what they allow. According to IONOS's help center you can choose the PHP version per domain in its PHP settings, older versions are available only through its paid PHP Extended Support, and IONOS does not change your version automatically. Pressable's knowledge base page (updated December 11, 2025) says it supports 8.2, 8.3 and 8.4 only (its API documentation lists newer versions, so check the control panel) and does not install ionCube, ZendGuard Loader or Imagick, so check whether any plugin you need relies on those extensions before you subscribe.

🔄 Want hosting that upgrades PHP for you when your version reaches end of support?
Kinsta: its docs say automatic PHP updates are on by default in MyKinsta, so a site on a version that reaches end of life is moved to the latest supported version (you can switch it off, and its long-term-support versions are not updated automatically)
☑️ See Kinsta plans

How do you find your site's PHP version and upgrade it safely? Six steps

The steps are based on WordPress.org's PHP update page and Hostinger's help pages, and they work for any WordPress site:

Find your current version. In the WordPress dashboard: Tools, then Site Health, then the Info tab, open the Server section and scroll to PHP version. If it is 8.3 or newer, WordPress.org says you do not need to upgrade right now.

Take a full backup. So you can return to your site's earlier state if something breaks, and make sure your host can switch back to the old PHP version if needed.

Update WordPress, the theme and the plugins. From Dashboard, then Updates, and check afterward that your site works as it should.

Check compatibility. WordPress.org advises adding the PHP Compatibility Checker plugin to scan themes and plugins, and Hostinger offers a compatibility-check tool in its WordPress section. It is best to try the new version on a staging copy first, if you have one.

Change the version from the hosting panel. At Hostinger: Websites, then Dashboard, then PHP Configuration, choose the version and click Update (it applies to all the sites on the plan except AI Builder sites). In cPanel it is usually under Software, then Select PHP Version. At Kinsta, open the site's Tools tab and choose PHP settings.

Test the site and go back if needed. Open the home page and the dashboard, and try a form, a login and a purchase if it is a store. If errors appear, return to the previous version from the panel, then deal with the plugin that caused it.

A note on Hostinger: its page says your existing sites on older versions stay as they are and you can only upgrade (no downgrade except within the same login session if a problem occurs), and that versions older than 8.2 are no longer available to choose.

Common PHP errors and what they mean

Message or symptom	What it means	What to do
"Allowed memory size exhausted"	A script went over the `memory_limit`	Raise the limit from the hosting panel (if your plan allows) or deactivate the heavy plugin
"Maximum execution time exceeded"	A script took longer than `max_execution_time`	Raise the time or split the operation (a large import, for example)
A large file will not upload	The size is over `upload_max_filesize` or `post_max_size`	Raise both from the PHP settings in the panel
A white screen or a 500 error after an upgrade	A plugin or theme that does not support the new version	Go back to the earlier version, then update the plugin or replace it
"PHP Update Required" in the WordPress dashboard	Your version is older than the recommended one	Follow the steps above

Hosts also limit the number of PHP workers: if all the workers are busy with simultaneous requests, a visitor may have to wait their turn. For a comparison of hosting types, read What Is a VPS.

🧱 Want managed WordPress with a clear ceiling on PHP workers?
Pressable: its Signature plans list five dedicated PHP workers per site with 512 MB of memory for each worker
☑️ See Pressable

🎯 Who needs to care about this, and who can wait?

✅ It matters to you if:

Your site is WordPress, Joomla, Drupal or WooCommerce
You see a "PHP update required" message or are thinking of changing host
You use old plugins that are no longer supported
You run a VPS and install the stack yourself

⚠️ It is less important if:

Your site is on Blogger, Shopify or Wix, where the platform runs the server
You use Hostinger's site builder (AI Builder), which does not let you change the PHP version
Your site is static HTML with no dynamic pages

🏆 The verdict: what to do after reading this

Check the PHP version on your site today, and if it is older than 8.3, plan to upgrade it with the steps above. And do not treat PHP as an "old" language: it is alive and gets a new release every year, but each release ends after four years, and staying on a version that has ended means staying without security updates.

Open Site Health now and write down your version.
Make a PHP upgrade part of your yearly maintenance, ahead of the date your version's support ends.
Ask your host: which versions are available? What are the limits (memory, time, upload, workers)? Are updates automatic?

🌐 Want hosting that lets you pick the PHP version with SSH and WP-CLI?
IONOS: its help center describes choosing the PHP version per domain in its PHP settings, and its web hosting page lists SSH, SFTP and WP-CLI
☑️ See IONOS hosting

✅ Frequently asked questions about PHP

❓ What is PHP?

An open-source scripting language suited to web development, embedded in HTML and executed on the server to generate pages on demand. Its name is a recursive acronym (PHP: Hypertext Preprocessor), and WordPress and most content management systems are built on it.

❓ Does PHP run on my computer or on the server?

On the server. The server runs the PHP code and sends only the HTML output to the browser, so the visitor never sees the code. That is what sets it apart from JavaScript, which runs in the browser.

❓ Do I need to learn PHP to run a WordPress site?

Not to run it or to manage it day to day, but you need to understand its version and settings (memory, time and upload size) and know how to upgrade it safely. Editing themes and writing plugins does need some knowledge of it.

❓ Who created PHP?

Rasmus Lerdorf created it in 1994 as CGI programs written in C to track visits to his online resume, and called them "Personal Home Page Tools." He released the source code to everyone in June 1995, according to the official PHP manual.

❓ What are the latest supported PHP versions?

According to php.net in October 2026: branches 8.2 through 8.5 are supported, with security fixes only for 8.2 (ending December 31, 2026) and 8.3 (until December 31, 2027), full support for 8.4 until December 31, 2026 and for 8.5 until December 31, 2027. The site also showed 8.6.0 RC3 for testing only.

❓ Which PHP version does WordPress recommend?

PHP 8.3 or newer, according to its requirements page. WordPress works with 7.4 and above, but those versions are past their official end of life and may expose your site to vulnerabilities.

❓ How do I find the PHP version on my site?

From the WordPress dashboard: Tools, then Site Health, then the Info tab, open the Server section and scroll to PHP version. Your hosting panel also shows it in its PHP settings section.

❓ Is upgrading PHP safe?

Usually yes, but it is not guaranteed: old themes or plugins may not work on the new version. Take a backup, update everything, check compatibility, try a staging copy if you can, and make sure you can go back to the earlier version.

❓ What is the difference between PHP and PHP-FPM?

PHP is the language and the interpreter that runs its code. PHP-FPM is an implementation of FastCGI that the web server uses to run PHP processes as a separate service with pools of workers, and PHP's documentation describes it as especially useful for heavily loaded sites.

❓ What do "PHP workers" mean in hosting specifications?

The number of PHP requests your plan can run at the same time. The more workers, the more dynamic visits your site can handle together without a visitor waiting. Hostinger lists 20, 40 and 60 workers in its shared plans, and Pressable lists five dedicated workers per site on its Signature plans.

❓ Does PHP affect my site's speed?

WordPress.org says newer versions are more efficient and can improve your site's speed. But speed is also affected by plugins, the theme, the database, caching and the CDN, so do not expect a miracle from an upgrade alone.

❓ Does PHP run on Shopify or Blogger?

These platforms do not let you run your own PHP code, because the platform runs the whole server. PHP matters when you host a site yourself or on hosting that runs a system built with it, such as WordPress.

🛡️ Start with what your host offers: a recent version and a clear worker count
And open Site Health now to learn your version before you decide anything
☑️ See Hostinger hosting

Which PHP version does your site run on? Tell us in the comments what Site Health showed you.

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