What is the PHP memory limit?

The PHP memory limit is the maximum amount of memory one PHP process may use while handling a request. WordPress, the active theme, and every plugin involved in that request share the allowance. It is different from the server’s total RAM and from storage space on the hosting account.

Memory use rises during imports, image processing, backups, complex page building, large database operations, and ecommerce tasks. When a process exceeds the limit, PHP usually stops it and records an “Allowed memory size exhausted” error. The visitor may see a blank page, a critical error message, or an incomplete action.

You can check the effective limit in WordPress Site Health, hosting tools, or PHP configuration information. WordPress also has its own memory constants, but the site cannot override a lower limit enforced by the server. Different PHP environments may use separate settings for the website, command line, and scheduled tasks.

Raising the limit can help a legitimate heavy operation. Diagnose the underlying use at the same time because a plugin with a leak or an unbounded query can consume any new allowance. Identify which action fails, review the error log, update or replace the responsible component, and increase memory only to a level available from the hosting plan.