Changes to supported PHPUnit versions have been as followed:
- In WordPress 4.4: Added support for PHPUnit 5 was added on PHPPHP The web scripting language in which WordPress is primarily architected. WordPress requires PHP 7.4 or higher 7.0.
- In WordPress 4.7: Added support for PHPUnit 6 on PHP 7.0 and 7.1.
- In WordPress 5.1: Added support for PHPUnit 7 on PHP 7.1, 7.2, and 7.3. PHP 7.0 remains at PHPUnit 6.
- In WordPress 5.2: Added support for PHPUnit 7 on PHP 7.0, and PHPUnit 5 on PHP 5.6.
- In WordPress 5.9: Added a dependency on the external PHPUnit Polyfills, which enabled support for PHPUnit 8 and 9, making it so the tests can now run on the most appropriate PHPUnit version for each PHP version.
- In WordPress 6.3: Dropped support for PHP 5.6 and thus PHPUnit 5.
- In WordPress 6.6: Dropped support for PHP 7.0 and 7.1 and thus PHPUnit 6 and 7.
Supported Version Chart
| WP | PHP Unit Version | 5.2 | 5.3 | 5.4 | 5.5 | 5.6 | 7.0 | 7.1 | 7.2 | 7.3 | 7.4 | 8.0 | 8.1 | 8.2 | 8.3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 6.7 | x | x | x | x | x | x | x | 8 | 9 | 9 | 9 | 9 | 9 | 9 |
| 6.6 | x | x | x | x | x | x | x | 8 | 9 | 9 | 9 | 9 | 9 | 9 |
| 6.5 | x | x | x | x | x | 6 | 7 | 8 | 9 | 9 | 9 | 9 | 9 | 9 |
| 6.4 | x | x | x | x | x | 6 | 7 | 8 | 9 | 9 | 9 | 9 | 9 | 9 |
| 6.3 | x | x | x | x | x | 6 | 7 | 8 | 9 | 9 | 9 | 9 | 9 | x |
| 6.2 | x | x | x | x | 5 | 6 | 7 | 8 | 9 | 9 | 9 | 9 | 9 | x |
| 6.1 | x | x | x | x | 5 | 6 | 7 | 8 | 9 | 9 | 9 | 9 | 9 | x |
| 6.0 | x | x | x | x | 5 | 6 | 7 | 8 | 9 | 9 | 9 | 9 | x | x |
| 5.9 | x | x | x | x | 5 | 6 | 7 | 8 | 9 | 9 | 9 | 9 | x | x |
| 5.8 | x | x | x | x | 5 | 5 | 7 | 7 | 7 | 7 | 7* | x | x | x |
| 5.7 | x | x | x | x | 5 | 5 | 7 | 7 | 7 | 7 | 7* | x | x | x |
| 5.6 | x | x | x | x | 5 | 5 | 7 | 7 | 7 | 7 | 7* | x | x | x |
| 5.5 | x | x | x | x | 5 | 5 | 7 | 7 | 7 | 7 | x | x | x | x |
| 5.4 | x | x | x | x | 5 | 5 | 7 | 7 | 7 | 7 | x | x | x | x |
| 5.3 | x | x | x | x | 5 | 5 | 7 | 7 | 7 | 7 | x | x | x | x |
| 5.2 | x | x | x | x | 5 | 5 | 7 | 7 | 7 | x | x | x | x | x |
| 5.1 | 3.6 | 4 | 4 | 4 | 4 | 6 | 7 | 7 | 7 | x | x | x | x | x |
| 5.0 | 3.6 | 4 | 4 | 4 | 4 | 6 | 6 | 6 | 6 | x | x | x | x | x |
| 4.9 | 3.6 | 4 | 4 | 4 | 4 | 6 | 6 | 6 | x | x | x | x | x | x |
| 4.8 | 3.6 | 4 | 4 | 4 | 4 | 6 | 6 | x | x | x | x | x | x | x |
| 4.7 | 3.6 | 4 | 4 | 4 | 4 | 6 | 6 | x | x | x | x | x | x | x |
| 4.6 | 3.6 | 4 | 4 | 4 | 4 | 5 | x | x | x | x | x | x | x | x |
| 4.5 | 3.6 | 4 | 4 | 4 | 4 | 5 | x | x | x | x | x | x | x | x |
| 4.4 | 3.6 | 4 | 4 | 4 | 4 | 5 | x | x | x | x | x | x | x | x |
| 4.3 | 3.6 | 4 | 4 | 4 | 4 | x | x | x | x | x | x | x | x | x |
| 4.2 | 3.6 | 4 | 4 | 4 | 4 | x | x | x | x | x | x | x | x | x |
| 4.1 | 3.6 | 4 | 4 | 4 | 4 | x | x | x | x | x | x | x | x | x |
| 4.0 | 3.6 | 4 | 4 | 4 | x | x | x | x | x | x | x | x | x | x |
| 3.9 | 3.6 | 4 | 4 | 4 | x | x | x | x | x | x | x | x | x | x |
| 3.8 | 3.6 | 4 | 4 | 4 | x | x | x | x | x | x | x | x | x | x |
| 3.7 | 3.6 | 4 | 4 | 4 | x | x | x | x | x | x | x | x | x | x |
* The coreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. test suite in these branches runs a modified version of PHPUnit 7 (which on its own is not compatible) on PHP 8. See #50902 for more information.
