A PHP update involves more than changing a setting in your hosting account. For a website that uses PHP, the selected version affects code compatibility, access to security fixes and, sometimes, performance. Whether you run WordPress, an online shop or a custom PHP application, prepare the change before applying it to your live website.
The basic approach is straightforward: check what is running now, establish what your application supports, test the change and keep a realistic way back.
1. What PHP does for your website
PHP is a programming language that runs on the server. In an application built with it, PHP code can retrieve information from a database, check logins, process forms and generate content sent to the browser. WordPress relies on PHP for much of its functionality.
A visitor’s browser receives the output of that processing, not the application’s PHP source code. Updating a browser therefore does not change your website’s PHP version: that belongs to the hosting environment.
Not every website uses PHP. A site made entirely of static files may have no dependency on it at all. For a PHP application, however, the runtime environment must be compatible with both the application and its components.
2. Available versions, the active version and application requirements
A server can have several PHP versions installed without your website using all of them. What matters is the version active for that particular website, not simply the list of versions available in your account.
Your application has its own requirements: a minimum version, sometimes an upper compatibility limit, and particular PHP extensions. The minimum version allows the application to run, but it is not necessarily the recommended choice for an up-to-date installation.
- Check the version reported by your application or hosting account tools.
- Read the application documentation for supported and recommended PHP versions.
- Check required extensions, such as those used for database connections, image processing or internationalisation.
- Record relevant settings, including memory limits and file upload limits.
Scheduled tasks and command-line operations may use a different PHP version from the website accessed through a browser. Check these separately if your application relies on them. When comparing web hosting options, include these hosting requirements in your assessment rather than considering storage space alone.
3. Why PHP security support matters
A PHP release branch passes through maintenance stages: active support, security support and eventually the end of official support. Check the PHP project’s official support information, as a version’s status changes over time.
A working website is not proof that its PHP version still receives security fixes. An old version may continue to execute code even after official maintenance ends. Some environments may have separately provided extended maintenance; do not assume this exists or covers every issue.
Choose a PHP version that is still supported and accepted by your application. The newest available release is not automatically suitable if plugins or custom code do not support it yet. Equally, updating PHP does not replace application updates, strong passwords or checks on administrative access.
4. How to check WordPress and application compatibility
For WordPress, your checks need to cover the core software, active theme, child theme and every plugin in use. An up-to-date WordPress installation may still contain an old plugin that prevents a move to a newer PHP version.
Information to collect
- The installed versions of the application, themes, plugins and third-party libraries.
- PHP requirements and compatibility notes published by their developers.
- The maintenance status of important components and possible replacements for abandoned ones.
- Custom modifications, external service integrations and automated tasks.
Use the application’s diagnostic information and available error logs to help identify issues. Automated analysis tools can detect some incompatibilities, but they do not replace functional testing. For a custom application, ask the developer to review the PHP migration guides for changes between versions as well.
If application components also need updating, follow their documentation to establish the right order. An intermediate release may sometimes be necessary. For a WordPress project, assess WordPress hosting against the needs of the whole website, including essential plugins, rather than the core software alone.
5. Prepare testing and a rollback plan
Before making changes, create or verify a complete backup stored separately from the environment you are modifying. It should include the files, database and configuration needed for recovery. Check the restoration method and your access to the backup; the existence of an archive does not establish that recovery will work.
Test in a separate environment
If you have the option, use a test copy that closely matches the live environment. Restrict access, prevent indexing and disable real emails, payments and automated actions that could affect customers. Protect any personal data copied into this environment too.
Apply the target PHP version there and check pages, logins, administration, forms, search and file uploads. For online shops, test the basket and checkout using test methods rather than real transactions.
Define how you will roll back
Record the original PHP version and relevant settings. Confirm whether that version will remain available to select after the change. Decide which errors would require you to stop the update and who can intervene.
If PHP is the only thing you changed, switching back may be sufficient. If you also updated the application or database structure, you may need to restore files and the database from the same point in time. For an active website, plan how to handle orders, messages or accounts created after the backup to reduce the risk of losing them.
6. Apply the update carefully and check the outcome
Choose a suitable time for your website’s activity and let the people involved know. Temporarily restrict content changes or orders if necessary. The exact controls depend on your hosting environment, but the general sequence remains the same:
- Confirm your backup and rollback procedure.
- Apply the prepared changes and select the tested PHP version for the correct website.
- Check extensions, settings and, separately, the PHP version used by scheduled tasks.
- Clear relevant caches if your application or infrastructure uses them.
- Repeat functional tests and review error logs.
- Monitor website behaviour, including tasks that run less frequently.
A correctly displayed homepage is not enough to confirm a successful PHP update. Check the actions that matter to visitors and administrators. If you cannot identify the active version or available options, use the contact page to ask for clarification about your hosting environment.
The practical takeaway: treat the change as a small technical migration. Choose a supported, compatible version, test the complete application and keep a verifiable rollback plan. That way, your decision is based on how the website actually works, not just the version number.
