PHP is the language most website software runs on. Versions are supported for a limited time and then stop receiving security fixes, so staying reasonably current matters.
Changing it
- Open your hosting service and choose Advanced Control.
- Find the PHP settings for the site.
- Select the version and save.
The change takes effect quickly. Check the site straight away.
Before you change it
- Take a backup of the files and the database.
- Check your software supports the version you are moving to - WordPress, plugins and themes all have their own requirements.
- Prefer moving up one version at a time.
- Do it when you can watch the site, not last thing on a Friday.
If the site breaks
Put the previous version back. That will restore the site, and gives you time to work out what was incompatible. A blank white page after a PHP change is nearly always a fatal error - turn on error display temporarily, or read the error log, to see which file is responsible.
Do not stay on an old version indefinitely
An unsupported PHP version stops getting security fixes and becomes a real risk. If something you rely on will not run on a current version, tell us and we will help you plan around it.
