Switch your website to a newer (or older) version of PHP, the language WordPress and most web apps run on, and adjust PHP settings such as the memory limit and maximum upload size. Changes take effect within a minute or two.
Before you start
- Check which PHP versions your website software supports. WordPress recommends PHP 8.3 or newer, but older themes and plugins may not work on the latest version. Update WordPress, your theme and plugins first.
- Take a snapshot first so you can roll back if needed: see Timeline backups.
Change your PHP version
- Log in to the Host Dada Control Panel. Go to cp.hostdada.uk (or Client Area → Services → your hosting → Login to Control Panel) and open your package.
- Open Change PHP Version. It's in the Web Tools section. The page shows You are currently using PHP version followed by your current version.
-
Choose a version and click Change PHP Version. Pick the version from the Select PHP version list. Versions from PHP 5.3 up to PHP 8.5 are available, but use a currently supported version (8.2 or later) unless your software needs an older one.
Pick the version and click Change PHP Version.
- Test your website. Open your site in a private browser window and click through a few pages, the contact form and (for shops) the checkout. If anything breaks, switch back to the previous version the same way.
Change PHP settings (memory limit, upload size and more)
- Open PHP Configuration in the Web Tools section.
-
Edit the values you need. Each setting has a short description. Switches turn features on or off (Activated or Not activated), and text boxes take a value such as
256M.
The PHP Configuration page.
- Click Update PHP Configuration at the bottom.
Settings at a glance
| Setting | Default | Change it when |
|---|---|---|
memory_limit | 128M | You see "Allowed memory size exhausted". Try 256M |
upload_max_filesize | 128M | Uploads (themes, media, backup files) are rejected as too large |
post_max_size | 128M | Keep it the same as or larger than upload_max_filesize |
max_execution_time | 300 seconds | Long imports or backups stop part way |
max_input_vars | 2500 | Large menus or page builder layouts don't save fully |
display_errors | Not activated | Only switch on briefly while troubleshooting. Turn it off afterwards |
Troubleshooting
My site shows a 500 error or "There has been a critical error" after changing version
A theme or plugin isn't compatible with the new version. Switch back to the previous version, update the theme and plugins, then try again. See Fix the WordPress white screen or critical error.
WordPress still says my PHP version is old
Give it a minute, then clear any caching plugin and purge the CDN cache (see Speed up your site with the CDN). Check the version shown on the Change PHP Version page.
A setting won't save or goes back to the old value
Check the format (for example 256M, not 256 MB). Some values have platform maximums. If you need more, open a ticket and tell us what your software requires.
Last reviewed: October 2026
