WordPress Hosting Requirements: PHP, Memory and Caching

The core WordPress hosting requirements are modest: a current PHP version, a supported MariaDB or MySQL database, and HTTPS. What separates a well-run host from an adequate one is everything around those basics, such as memory headroom, caching, backups and support. This guide (last updated 10 November 2026) separates the true minimums from the factors that matter in daily use.

The official WordPress hosting requirements in plain terms

The WordPress project publishes a short list. According to the WordPress.org requirements page, it is recommended that your host supports:

• PHP version 8.3 or greater
• MariaDB 10.11 or greater, or MySQL 8.0 or greater
• HTTPS support

Apache or Nginx is recommended, although any server that supports PHP and MySQL will do. These are the wordpress server requirements in full; everything else in this article is about running a site well rather than merely running it.

Legacy versions are not a safe fallback

The same page says WordPress also works on PHP 7.4+ and MySQL 5.5.5+ in legacy environments, but those versions have reached end of life and may expose your site to security vulnerabilities. If a plan only offers them, treat that as a reason to look elsewhere. The requirements change over time, so re-check the page before you commit to a plan instead of relying on any article, including this one.

Turn each requirement into a question

Check what your site runs today

In the dashboard, open Tools → Site Health → Info and expand the Server section. It lists your PHP version, database version and web server software, so you can compare them with the requirements page instead of guessing.

Account isolation

The requirements page also says hosting is more secure when PHP applications run under your account's own username rather than a default shared one. It suggests asking a potential host what steps it takes to secure your account. A clear, specific answer is a good sign of a well-run platform.

PHP version for WordPress: how to choose and change it

The right php version wordpress setup is the newest version your theme and plugins support, and at least the version WordPress recommends. A host that offers only one fixed PHP version is a risk: you cannot move forward when WordPress does, or step back briefly when an old plugin breaks.

How to upgrade PHP safely

1. Take a full backup of files and database, and confirm you know how to restore it.
2. Update WordPress core, themes and plugins first, and remove any you no longer use.
3. Test on a staging copy if your host offers one. If not, upgrade at a quiet time.
4. Switch the PHP version in your hosting control panel.
5. Browse the front end, log in, submit a form, run a test checkout if you sell online, and check the error log.
6. If something fails, switch back, find the outdated plugin or theme, and replace or update it before trying again.

Extensions and settings

The requirements page points to the Hosting Handbook for detailed PHP extension recommendations, so ask your host to confirm them rather than assuming. Also ask whether OPcache is enabled. The WordPress caching documentation says an opcode cache can improve PHP performance many times over.

When evaluating a plan, the flexibility to choose PHP per site matters more than any single version number printed on a plan page.

WordPress memory limit: what it is and when to raise it

The wordpress memory limit is the memory a single PHP process may use while building a page. It is separate from your plan's overall RAM or disk space. A limit that is too small shows up as a white screen or an allowed memory size exhausted error, typically during a plugin update, image import, backup run or heavy admin page.

The wp-config.php documentation has a section on increasing the memory allocated to PHP. The usual approach is a line in wp-config.php, above the comment that says to stop editing:

define( 'WP_MEMORY_LIMIT', '256M' );

The value is an example, not an official requirement. Two cautions:

• WordPress can only use what the server allows. If your host caps PHP memory lower, the constant will not override it. Ask your host to raise the PHP limit, or change it in the control panel if the option exists.
• A higher limit does not cure a slow site. If a page needs a very large amount of memory, look for the cause: an oversized plugin, an unoptimised import or a runaway query.

Signs the limit really is the problem

• Errors appear mainly in wp-admin, for example when updating or importing, rather than on public pages.
• The error log names memory exhaustion and points at a specific plugin.
• A WooCommerce store, page builder or large media library is involved.

Back up wp-config.php before editing. The documentation warns that advanced changes can cause unforeseen issues and that you should know how to restore a backup first.

Caching and object cache: the layers that speed up WordPress

The WordPress developer documentation calls caching the fastest way to improve performance. It describes several distinct layers, and confusing them wastes effort.

Do you need an object cache?

An object cache is persistent storage for data that is slow to retrieve, such as repeated database query results. The documentation lists Redis and Memcached among popular engines and stresses that cached data must be regenerable: if the cache is lost, the site keeps working, just more slowly while it refills.

A brochure site with a handful of pages usually gains most from a page cache alone. An object cache earns its place on sites with logged-in users, memberships, large catalogues or busy stores, where pages cannot simply be served as static files. In that case, confirm your host offers Redis or Memcached and will help you connect it.

Avoid stacking caches blindly

Two page-cache plugins, or a plugin plus a host cache doing the same job, can cause stale pages and confusing behaviour. Pick one page-cache layer, test logged-in and checkout pages separately, and clear caches after each change. For a wider tuning plan, see our step-by-step site speed checklist.

What really matters when comparing WordPress hosts

Meeting the version numbers is the starting point. These factors decide whether running a business site feels calm or stressful.

• Backups you can restore. Ask how often backups run, how long they are kept and whether you can restore a single site yourself.
• HTTPS that renews itself. The certificate should be installed and renewed without manual work.
• Account isolation. Ask how your site is separated from other accounts on the same server.
• PHP flexibility. Selectable versions, adjustable memory and visible error logs.
• Support that can read a log. When a plugin update causes a fatal error, you want someone knowledgeable available when you need them.
• Migration help. Moving an existing site is the riskiest step. A free website migration service removes much of that risk.

What matters less than it appears

Headline storage figures and visitor-count claims are hard to compare between providers because workloads differ. A lean site with a page cache can outperform a heavy one on a larger plan. Judge a plan by the limits that affect PHP (memory, process limits, caching options) and by how the provider behaves when a limit is reached, not by the biggest number on the page.

Matching your site to a plan type, with a pre-purchase checklist

Choose the plan type by how the site is built and managed, not just by traffic.

A VPS gives control over PHP, caching services and server software, but that control brings responsibility for updates and security unless the service is managed.

Two worked examples

A consultancy runs a twelve-page site with a contact form and a blog. It needs current PHP, HTTPS, backups and a page cache. It does not need Redis or root access, so standard web hosting is a reasonable start, with an upgrade path later.

An online shop with many products and logged-in customers is different. Page caching helps the catalogue but not the cart or account pages, so an object cache and control over PHP settings become important. That points towards a WordPress-focused or VPS environment.

Questions to send a host before you buy

The requirements page offers a copy-and-paste request covering the core versions. Extend it with these:

1. Which PHP versions can I choose, and can I change them per site?
2. Which MariaDB or MySQL version is used?
3. Is HTTPS included, and does it renew automatically?
4. What is the PHP memory limit, and can it be raised if a plugin needs more?
5. Is OPcache enabled, and are Redis or Memcached available?
6. How are backups taken, and how do I restore one?
7. Is there staging, or an easy way to clone the site?
8. Will you migrate my existing site, and how is downtime handled?

If you want help matching the answers to your site, our plan finder is a good place to start.

Ready to compare options for your WordPress site? Take a look at our web hosting plans and see which setup fits your requirements.

Frequently asked questions

What are the minimum WordPress server requirements?

WordPress.org recommends PHP 8.3 or greater, MariaDB 10.11 or greater or MySQL 8.0 or greater, and HTTPS support. Apache or Nginx is recommended, though any server supporting PHP and MySQL will work. Older versions may run but are end of life and carry security risks.

Which PHP version should I use for WordPress?

Use the newest version your theme and plugins support, and at least the version WordPress recommends. Back up first, test on staging if you can, and switch back if a plugin fails until it is updated or replaced.

How do I increase the WordPress memory limit?

Set WP_MEMORY_LIMIT in wp-config.php, as described in the WordPress developer documentation. It only works within the maximum your host allows, so you may also need the host to raise the PHP memory limit. Back up the file before editing it.

Do I need an object cache for WordPress?

Not for every site. Small sites with mostly static pages usually benefit most from a page cache. An object cache using Redis or Memcached is worth considering for stores, membership sites and other pages generated per user.

Is shared hosting enough for WordPress?

For many small business sites, yes, provided the plan meets the version requirements, supports caching and includes backups and HTTPS. If you need root access, custom services or heavier workloads, a VPS gives you more control.