PHP limits control how much resources a PHP script may use.
These limits protect server stability and prevent scripts from consuming excessive resources.

Understanding these limits helps when troubleshooting website errors.

Why PHP Limits Exist #

PHP limits:

• Prevent server overload
• Improve stability for all users
• Protect against runaway scripts
• Define safe execution boundaries

Limits apply to every PHP-based website.

Memory Limit (memory_limit) #

This defines the maximum amount of memory a PHP script may use.

If the limit is too low:

• Scripts may fail
• Pages may load incompletely
• Errors may appear

Increasing this limit may help with complex websites.

Upload File Size (upload_max_filesize) #

This controls the maximum size of a file that can be uploaded via PHP.

Commonly affects:

• Media uploads
• Plugin installations
• Theme uploads

Uploads larger than this limit will fail.

Post Size (post_max_size) #

This defines the maximum size of all POST data combined.

It must be larger than or equal to upload_max_filesize.

If set too low, uploads may fail silently.

Execution Time (max_execution_time) #

This defines how long a script may run before being stopped.

If exceeded:

• Scripts are terminated
• Long tasks fail
• Timeout errors occur

Increasing this limit may help with imports or updates.

Input Variables (max_input_vars) #

This controls how many input variables PHP accepts.

Low values can cause:

• Form submissions to fail
• Missing data in large forms
• Issues with complex CMS interfaces

How to Identify PHP Limit Issues #

PHP limit issues often present as:

• White screens
• Incomplete page loads
• Error messages
• Failed uploads

Error logs may indicate which limit was reached.

How to Adjust PHP Limits #

PHP limits can be adjusted via:

• MultiPHP INI Editor

Changes apply immediately.

Common Mistakes #

• Increasing all limits unnecessarily
• Setting extremely high values
• Ignoring error messages
• Adjusting limits without testing

Higher limits are not always better.

When Not to Increase Limits #

Do not increase limits if:

• Errors are unrelated
• The website works correctly
• You do not know which limit is required

Incorrect adjustments can cause instability.

Responsibility Notice #

You are responsible for:

• Adjusting PHP limits correctly
• Monitoring website performance
• Testing after changes

ProRedLine does not optimize PHP limits automatically.