How to Change PHP Version, Memory Limit & Max Upload Size

To increase the PHP memory limit, the safest route is your hosting control panel: open the PHP settings and raise memory_limit to 256M. If your host has no panel option, add define('WP_MEMORY_LIMIT', '256M'); to wp-config.php, or set memory_limit = 256M in php.ini or .user.ini. Always back up first.

If you have ever seen a message like "Allowed memory size exhausted", a plugin that refuses to activate, or a theme upload that fails halfway, you have run into a PHP limit. These limits are guardrails your host sets so one site cannot use up all the server's resources. They are normal, and they are yours to adjust.

Setting them correctly fixes some of the most common WordPress headaches. A memory limit that is too low is a frequent cause of the WordPress white screen of death and the 500 internal server error. An upload limit that is too small blocks large themes, plugins, and media files. An outdated PHP version leaves your site slower and less secure than it needs to be.

This guide is for site owners on shared hosting, managed WordPress, or a VPS who want to change these values safely. Every task here has a control-panel method and a file-editing fallback. For a wider view of the errors these limits can trigger, see our server errors guide.

PHP is the server-side language that WordPress is built in. Every time someone loads a page, the server runs PHP to build it. PHP reads its rules from configuration files, and those rules include the limits below.

php.ini is the main PHP configuration file. It sets the default values for the whole server or your account. .user.ini is a smaller per-folder config file used on many shared hosts (those running PHP as CGI/FastCGI); it lets you override selected values just for your own site without touching the main file.

Here are the values this guide changes:

The letter M means megabytes, so 256M is 256 megabytes. You can raise any of these, but do it in steps and only as far as your plan allows.

Before you change anything, find out what your site uses today. There are three easy ways.

1. Create a phpinfo page (most complete). Make a plain text file named info.php, put a single line in it, <?php phpinfo(); ?>, and upload it to your site's root folder. Visit yourdomain.com/info.php in a browser. It lists every value, including memory_limit, and the exact config file that is loaded (look for the "Loaded Configuration File" line). Delete the file when you are done, because it exposes server details.
2. Use the hosting panel. Many panels have a PHP information or PHP configuration screen that shows current values without uploading anything.
3. Use WordPress Site Health. In your dashboard, go to Tools → Site Health → Info → Server. It shows your PHP version, memory limit, upload size, and time limit.

The safe, recommended way to switch PHP versions is through your hosting control panel, not by editing files. As of 2026, higher PHP versions such as 8.2 and 8.3 are usually noticeably faster and receive security updates, while older versions like 7.4 have reached end of life.

1. Take a full backup of your files and database.
2. Log in to your hosting control panel (for example hPanel or cPanel).
3. Open PHP Configuration or Select PHP Version.
4. Choose the version you want to test, for example 8.2 or 8.3, and save.
5. Visit your site and click through key pages, the checkout or contact form, and the admin area. Watch for errors.
6. If something breaks, switch back to the previous version the same way, then update the plugin or theme that caused it before trying again.

If your panel offers separate PHP versions per site or per folder, change only the one for the site you are working on.

This is the change most people need. Try the methods below in order. The first one that works is the right one for your host; you do not need to do all five. A value of 256M is comfortable for most WordPress sites.

1. Hosting panel first. Open your control panel's PHP settings (PHP Configuration or MultiPHP INI Editor), find memory_limit, set it to 256M, and save. This is the cleanest method and survives most updates.
2. Edit wp-config.php. If there is no panel option, open wp-config.php in your site root and add define('WP_MEMORY_LIMIT', '256M'); just above the line that reads /* That's all, stop editing! */. To give the admin area more room, also add define('WP_MAX_MEMORY_LIMIT', '512M');.
3. Edit php.ini. If WordPress still runs low, set the server limit directly. In php.ini, add or change the line memory_limit = 256M, then save.
4. Edit .user.ini. On hosts that use per-folder config, add memory_limit = 256M to a .user.ini file in your site root. Changes can take a few minutes to apply.
5. Edit .htaccess (Apache only). As a last resort on Apache servers, add php_value memory_limit 256M to your .htaccess file. Skip this on Nginx or LiteSpeed setups, which ignore it.
6. Confirm the change. Reload your site, clear any caching plugin or server cache, and re-check the value with your phpinfo page or Site Health.

To raise the max upload size you must change three values together: upload_max_filesize (the largest single file), post_max_size (the largest total submission), and often max_execution_time (so big uploads have time to finish). The golden rule: post_max_size must be equal to or larger than upload_max_filesize.

As with memory, start in the panel and only edit files if you must.

1. Hosting panel first. In your PHP settings, set upload_max_filesize to 64M, post_max_size to 64M (or higher), and max_execution_time to 300, then save.
2. php.ini. If there is no panel option, add these lines to php.ini: upload_max_filesize = 64M, post_max_size = 64M, and max_execution_time = 300.
3. .user.ini. On per-folder hosts, put the same three lines in your .user.ini file instead.
4. .htaccess (Apache only). As a fallback on Apache, add php_value upload_max_filesize 64M, php_value post_max_size 64M, and php_value max_execution_time 300.
5. Verify. In WordPress, go to Media → Add New; the page shows the current maximum upload size. Confirm it now reads your new value.

If you only need to import a large database or run a slow tool once, raising max_execution_time temporarily is often enough on its own.

• Setting post_max_size smaller than upload_max_filesize. The upload will silently fail. Always keep post_max_size equal to or larger.
• Using the .htaccess method on a server that ignores it. Many managed WordPress, Nginx, and LiteSpeed setups do not read php_value lines. Use the panel or .user.ini instead.
• Not clearing the cache. A caching plugin or server cache can keep serving the old page, so your change looks like it did nothing. Clear it and reload.
• Editing the wrong file. If your host loads .user.ini but you edit php.ini, nothing happens. Check the "Loaded Configuration File" line in phpinfo first.
• Raising limits far beyond what you need. Very high values can hide a badly behaved plugin and, on some plans, are capped or refused anyway. Move up in steps.

A few habits keep these settings trouble-free:

• Use the control panel first. It is the method most likely to work and survive updates, and it is hard to break your site with it.
• Only edit files if you need to. Reach for wp-config.php, php.ini, .user.ini, or .htaccess when the panel has no option.
• Keep a backup. Before any file edit, save a copy of the original and a full site backup so you can roll back in seconds. See the website backups guide.
• Test on a staging copy when you switch PHP versions, if your host offers one.
• Right-size your values. Set what you need with a little headroom, not the highest number possible.

If you regularly hit these limits even after raising them, the real issue may be that your plan is too small for your traffic or plugins. That is a hosting-capacity question rather than a settings one.

How much PHP memory does WordPress need?

WordPress itself asks for at least 64M, but a real site with a theme and several plugins is comfortable at 256M. Heavy setups such as WooCommerce or page builders may want 512M. Start at 256M and raise it only if you still see memory errors.

Why isn't my memory-limit change working?

Almost always because the value was set in a file the server does not load, or a cache is serving the old page. Open a phpinfo page, read the "Loaded Configuration File" line, edit that exact file, then clear every cache and reload. Some shared plans also cap the maximum, so a very high value may be refused.

Is upgrading the PHP version safe?

Usually yes, and it is worth doing, because newer versions are faster and more secure. The risk is an old plugin or theme that has not been updated. Back up first, confirm your key plugins support the version, ideally test on staging, and keep the option to switch back if a page breaks.

Where is the php.ini file?

Its location varies by host. The reliable way to find it is a phpinfo page: the "Loaded Configuration File" line shows the exact path. On many shared hosts you will not edit php.ini directly at all; you use the panel or a per-folder .user.ini file in your site root instead.

How do I increase the WordPress upload limit?

Raise upload_max_filesize and post_max_size to the same value, for example 64M, keeping post_max_size equal to or larger, and raise max_execution_time if big files time out. Do it in your hosting panel first; if there is no option, use php.ini or .user.ini. Check the result under Media → Add New.

What is the difference between php.ini and .user.ini?

php.ini is the main configuration file that sets defaults for the whole server or account. .user.ini is a smaller per-folder file that overrides selected values just for your site, used on hosts that run PHP as CGI or FastCGI. If your host uses .user.ini, edit that; changes may take a few minutes to apply.

Changing PHP settings is straightforward once you know the order: check your current values with a phpinfo page, then make the change in your hosting control panel first and fall back to wp-config.php, php.ini, or .user.ini only if needed. Raise memory_limit to 256M to stop crashes, keep post_max_size at least as large as upload_max_filesize for uploads, and back up before switching PHP versions.

If a wrong value has already broken your site, your next step is our server errors guide, which maps each symptom to a fix, including the JSON response error you can hit after a failed upload.

• PHP Manual — Runtime configuration and .user.ini files (php.net documentation).
• WordPress.org — Editing wp-config.php, including WP_MEMORY_LIMIT and WP_MAX_MEMORY_LIMIT.
• WordPress.org — Site Health screen and server info.
• PHP.net — Supported versions and end-of-life schedule (checked 2026).