What this problem is
WordPress displays: Allowed memory size exhausted and a page fails to load.
Why it happens
- PHP memory_limit is too low for your workload
- Plugin/theme performs heavy operations
- Large autoloaded options or heavy queries
Prerequisites
- Access to hosting PHP settings and wp-config.php
Diagnosis
Check the error log line to identify the script/plugin and the memory limit value.
Detailed steps
Step 1) Increase PHP memory_limit
In hosting panel, raise memory_limit (example: 256M or 512M depending on the site).
Step 2) Increase WordPress memory (wp-config.php)
define("WP_MEMORY_LIMIT", "256M");Step 3) Reduce memory usage
- Disable heavy plugins temporarily and retest
- Optimize images and page builder usage
- Clean large autoloaded options if needed
Expected results
- Pages load without memory exhaustion
What to do if it fails
- Ask hosting for real memory usage and whether the account hits process limits; consider upgrading plan
Best practices
- Monitor memory after updates and avoid plugins that continuously spike usage