Fix Configuration Not Saving in Magento 2

Saving your Magento 2 configuration but nothing changes? You might see a success message, yet values revert to their previous state. This is often caused by PHP's max_input_vars limit being exceeded.

The Problem

Magento 2 configuration pages can contain hundreds or even thousands of form fields, especially when you have multiple store views or websites. PHP's max_input_vars directive (default: 1000) limits how many input variables can be submitted in a single request.

When this limit is exceeded, PHP silently truncates the POST data. Magento receives incomplete data but doesn't know anything is missing, so it appears to save successfully while only partial (or no) changes are actually stored.

Symptoms

• Configuration shows "success" message but values didn't change
• Some fields save correctly, others revert to previous values
• Problem occurs on pages with many fields (System Config, extension settings)
• Works fine on smaller configuration pages
• Issue is worse with multiple store views/websites

Quick Diagnosis

Check Current Limit

php -i | grep max_input_vars

<?php phpinfo();

Check POST Data Size

Solution

Increase max_input_vars in your PHP configuration.

Via php.ini

max_input_vars = 10000

Via .htaccess (Apache with mod_php)

php_value max_input_vars 10000

Via .user.ini (PHP-FPM)

max_input_vars = 10000

Recommended Values

Verify the Fix

After making changes:

1. Restart PHP/webserver
2. Check the new value: php -i | grep max_input_vars
3. Try saving your configuration again
4. Verify values are actually stored

bin/magento config:show path/to/your/config

Troubleshooting

Still Not Working

Suhosin Extension

suhosin.post.max_vars = 10000
suhosin.request.max_vars = 10000

Cloudflare / WAF

Related Settings

Other PHP settings that can affect form submissions:

; Maximum POST data size
post_max_size = 64M

; Maximum number of files in one request
max_file_uploads = 20

; Maximum execution time (large configs may timeout)
max_execution_time = 300

Prevention

For stores with many store views, consider:

• Using bin/magento config:set for bulk configuration changes
• Storing configuration in app/etc/config.php (environment-specific config)
• Using deployment pipelines to manage configuration

Need More Help?

Documentation:

• All Help Articles - Complete documentation overview

Support:

• Contact Support - Get help from our team