Quick symptom — what does Bitrix do when max_input_vars is hit?

Silently saves only the first N fields and discards the rest. No error in the UI; the saved record looks normal until you notice fields are blank or have stale values. Diagnostic clue: count() of $_POST in a phpinfo() page shows close to your max_input_vars cap. Bitrix's Settings panel especially submits 500-3000 fields; bumping to 5000-10000 is normal for production.

Where exactly to set it for Bitrix?

php.ini for global. .user.ini in DOCUMENT_ROOT for per-site override. Bitrix-installed via BitrixVA: edit `/etc/php.d/00-bitrix.ini` (or equivalent). After change, restart PHP-FPM or Apache. Verify with phpinfo() showing the new value, then test Bitrix admin form that previously truncated.

Recommended max_input_vars for Bitrix?

Small site (single iblock, < 50 properties): 3000 is enough. Medium (catalog with categories, multiple iblocks): 10000. Large (multi-shop, rich property hierarchies): 20000-50000. Bitrix's official docs say 10000 as baseline; raise if you still see truncation. Higher values use slightly more memory per request but trivially.

Does this affect just admin or front-end too?

Mostly admin — front-end forms rarely have 1000+ fields. But large checkout forms with many product configurators, or import wizards exposed to merchants, can hit it. If a front-end form silently loses data, max_input_vars is the first thing to check before looking at form validation code.

max_input_vars in Bitrix: What It Is and How to Adjust It

Q: Does this affect just admin or front-end too?

Mostly admin — front-end forms rarely have 1000+ fields. But large checkout forms with many product configurators, or import wizards exposed to merchants, can hit it. If a front-end form silently loses data, max_input_vars is the first thing to check before looking at form validation code.

3 min read

24.08.2025

The max_input_vars setting in PHP controls the maximum number of input variables (e.g., GET, POST, or COOKIE variables) that PHP can handle in a single request. In Bitrix, a low max_input_vars value can cause issues with large forms, settings pages, or when saving configurations, especially in admin panels.

Bitrix max_input_vars Configuration — max_input_vars — silent truncation; Bitrix admin loses fields above 1000.

For other Bitrix-tuning topics, see Setting mbstring.func_overload for Bitrix, Bitrix Error Log — Locate, Enable, Analyze, and Bitrix Virtual Appliance (BitrixVA).

Common Errors Caused by Low max_input_vars

Form Submission Issues:
- Some fields may not save, or partial data is submitted.
- Example error: "Data is missing or incomplete."
Admin Panel or Module Issues:
- Errors when saving settings with many fields.
Menu and Permission Settings:
- Long menus or permissions configurations fail to save.

Default Value of max_input_vars

Default value: 1000
This is often insufficient for Bitrix installations with complex configurations.

Recommended Value for Bitrix

Recommended value: 5000 or higher.
For very large forms or configurations, you may need to increase it further.

How to Adjust max_input_vars

Update php.ini

Locate your PHP configuration file:
```
php --ini
```
Open php.ini for editing:
```
sudo nano /etc/php/7.x/apache2/php.ini
```
Increase the max_input_vars value:
```
max_input_vars = 5000
```

Restart the web server:

sudo systemctl restart apache2

sudo systemctl restart php7.x-fpm

Update .htaccess (If You Cannot Edit php.ini)

Open the .htaccess file in your website root directory.
Add the following line:
```
php_value max_input_vars 5000
```

Update user.ini (If .htaccess Does Not Work)

Create or edit a .user.ini file in your website root directory.
Add the following line:
```
max_input_vars = 5000
```
Restart PHP:
```
sudo systemctl restart php7.x-fpm
```

Use ISPmanager or cPanel

If your server is managed via a control panel like ISPmanager or cPanel:

Go to PHP Settings or PHP Selector.
Find max_input_vars and increase it to 5000.
Save and restart PHP from the panel.

Verify the Change

Create a phpinfo.php file in your root directory:
```
<?php

phpinfo();

?>
```
Open it in your browser:
```
http://yourdomain.com/phpinfo.php
```
Look for max_input_vars in the output to confirm the new value.

Troubleshooting

Issue	Solution
Changes not applied	Ensure you are editing the correct php.ini or .htaccess file.
Bitrix still shows errors	Double-check the new value in phpinfo() output.
Large forms still fail	Increase the value further (e.g., `max_input_vars = 10000`).
Multiple PHP versions on server	Update php.ini for the correct PHP version.

The max_input_vars setting is crucial for Bitrix to handle large forms and configurations.
Set the value to 5000 or higher to avoid errors.
Use php.ini, .htaccess, or control panel tools to adjust the value.

max_input_vars in Bitrix: What It Is and How to Adjust It

Common Errors Caused by Low max_input_vars

Default Value of max_input_vars

Recommended Value for Bitrix

How to Adjust max_input_vars

Update php.ini

Update .htaccess (If You Cannot Edit php.ini)

Update user.ini (If .htaccess Does Not Work)

Use ISPmanager or cPanel

Verify the Change

Troubleshooting

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max_input_vars in Bitrix: What It Is and How to Adjust It

Common Errors Caused by Low max_input_vars

Default Value of max_input_vars

Recommended Value for Bitrix

How to Adjust max_input_vars

Update php.ini

Update .htaccess (If You Cannot Edit php.ini)

Update user.ini (If .htaccess Does Not Work)

Use ISPmanager or cPanel

Verify the Change

Troubleshooting

Hosting

Cloud Solutions

For You

VDS

Website Builders

Our services

Client Area

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