Switching PHP Version

Steps#

1. Go to Hosting Mode → PHP.
2. Click the domain you want to change.
3. Under PHP Version, select the target version from the dropdown.
4. Click Save.

The agent immediately:

1. Writes a new FPM pool config at /etc/php/{new-version}/fpm/pool.d/{domain}.conf.
2. Updates the domain's Nginx vhost to point fastcgi_pass at the new version's Unix socket.
3. Reloads PHP-FPM (both old and new version) and reloads Nginx gracefully.

The switch is seamless — Nginx performs a graceful reload, so in-flight requests complete under the old version before the new pool takes over.

[!NOTE] If the target PHP version is not in the dropdown, it has not been installed on the server yet. Contact your server admin to install it. See Installing PHP Versions.

What Does Not Carry Over#

PHP-FPM pools are version-specific. When you switch versions, the new pool starts with the default php.ini values for that version. The following settings from your old version's pool do not migrate automatically:

• memory_limit
• upload_max_filesize
• post_max_size
• max_execution_time
• display_errors
• Any other custom php.ini overrides

After switching, re-apply your settings under Hosting Mode → PHP → [domain] → PHP Settings. See Editing php.ini.

Similarly, PHP extensions enabled for the old version are not automatically enabled on the new version. Re-enable any required extensions under PHP → [domain] → Extensions. See PHP Extensions.

Verifying the Switch#

Create a temporary info.php in your public_html/:

<?php phpinfo();

Load it in a browser. Confirm the PHP version at the top. Delete the file when done.

# Or check via SSH
php8.3 -v

[!TIP] Test the switch on a staging domain first if the application has strict PHP version requirements or uses extensions that may not be available in the new version.