> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://help.faaaster.io/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# How do I change my Faaaster site's PHP version?

The PHP version is set from the site's **Server** tab, **Runtime environment** section, **PHP engine** row. The **Edit** button opens the version picker.

> Faaaster recommends **PHP 8.2 or later**.

## Changing version

1. Open the site, **Server** tab.
2. **Runtime environment** section, **PHP engine** row.
3. Click **Edit**, choose the version in the **Switch PHP Version** window, then click **Apply**.

With the **Viewer** role, you can view the **Server** tab but its settings are grayed out.

![The Runtime environment section: the PHP version and the Edit button.](https://storage.crisp.chat/users/helpdesk/website/-/9/d/2/d/9d2d3e0b7134b800/act-config-php-en_9mfee9.png)

> **Before changing major version**, create a backup and check that your plugins and theme are compatible. A version jump can break a site that uses old code.

## Server environment

The **Server environment** row, just below, reads: "Aligns the system image (nginx, PHP, extensions) with the latest available version." The **Update** button applies it.

## Available versions

PHP **5.6**, **7.1**, **7.2**, **7.3**, **7.4**, **8.0**, **8.1**, **8.2**, **8.3**, **8.4** and **8.5**.

> Versions 5.6 to 7.4 carry the **end of life** badge on the **PHP engine** row: they haven't received security fixes for years and are only there for older sites waiting to be upgraded. Faaaster recommends **8.2 or later**.

## Does the site restart?

**Not always.** Before applying, the version change window shows one of these two messages:

- usually on the live production site, outside the Dev plan: "Your site stays online while the update is applied: the new configuration is prepared alongside it, then the site switches over (about 5 minutes). If switching over without downtime isn’t possible, the site restarts briefly.";
- otherwise — development environment, site on the Dev plan, stopped site or site hosted on the legacy infrastructure: "Configuration changes will be applied after a restart. Your site might be unavailable for a few minutes."

The **Update** button on the **Server environment** row follows the same rule.

> **Pick your moment.** An off-peak hour, never right before a sales event or an expected traffic spike.

👉 [How do I restart my site?](https://help.faaaster.io/en-us/article/restart-your-site-1tp89sn/) · [How do I back up and restore a site?](https://help.faaaster.io/en-us/article/backups-1j7rzgw/)