Title: PHP
Author: WordPress VIP Documentation
Published: August 9, 2022
Last modified: July 21, 2025

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 1. [WordPress on VIP](https://docs.wpvip.com/wordpress-on-vip/)
 2. PHP

#  PHP

PHP is under active development, and runs on all WordPress environments. As new 
versions are released, WordPress VIP customers are encouraged to [prepare their application code for a PHP version update](https://docs.wpvip.com/code-scanning-for-php-upgrade/)
as soon as possible.

Customers are encouraged to follow [WordPress.org’s Developer Resources for PHP Coding Standards](https://developer.wordpress.org/coding-standards/wordpress-coding-standards/php/).
Application code can be scanned against the official [WordPress Coding Standards](https://github.com/WordPress/WordPress-Coding-Standards),
as well as the [VIP-Coding-Standards (VIPCS)](https://github.com/Automattic/VIP-Coding-Standards/releases),
by following the instructions to [install and run PHPCS for WordPress VIP](https://docs.wpvip.com/php_codesniffer/).

The active versus idle PHP processes on an environment can be reviewed in [the **Insights & Metrics** panel of the VIP Dashboard](https://docs.wpvip.com/performance/insights-metrics/).

## Memory limit

By default, PHP’s `memory_limit` on VIP Platform WordPress environments is set to
768MB. `WP_MEMORY_LIMIT` is set to 40MB for [WordPress single sites](https://docs.wpvip.com/wordpress-single-site/),
and 64MB for [WordPress multisites](https://docs.wpvip.com/wordpress-multisite/).
If a site’s `WP_MEMORY_LIMIT` is set to a value higher than `memory_limit`, WordPress
will allow `WP_MEMORY_LIMIT` to override the PHP `memory_limit`.

## Extensions

A limited group of PHP extensions are enabled by default on all web containers. 
PHP extensions that are not listed below cannot be enabled.

| apcu | 
| bcmath | 
| calendar | 
| Core | 
| ctype | 
| curl | 
| date | 
| dom | 
| exif | 
| filter | 
| ftp | 
| gd | 
| gmagick | 
| gmp | 
| gnupg | 
| hash | 
| iconv | 
| igbinary | 
| intl | 
| json | 
| libxml | 
| mbstring | 
| mcrypt | 
| memcache | 
| memcached | 
| mysqli | 
| mysqlnd | 
| newrelic | 
| openssl | 
| pcntl | 
| pcre | 
| PDO | 
| pdo_mysql | 
| pdo_sqlite | 
| Phar | 
| posix | 
| Reflection | 
| session | 
| shmop | 
| SimpleXML | 
| soap | 
| sockets | 
| sodium | 
| SPL | 
| sqlite3 | 
| ssh2 | 
| standard | 
| sysvsem | 
| sysvshm | 
| timezonedb | 
| tokenizer | 
| xml | 
| xmlreader | 
| xmlwriter | 
| Zend OPcache | 
| zip | 
| zlib |

Last updated: July 21, 2025