Definition
This measure counts WordPress plugins by the minimum PHP version each declares in its "requires PHP" field. It also counts the plugins that leave the field undeclared. It shows how the declared PHP floor is spread across the whole WordPress.org directory at a single point in time. The field is set by the plugin author and can change with any release.
Population and window
Rivale measures PHP requirement across the whole directory, meaning every plugin listed on WordPress.org on the issue's data date. The window is a single date, the last day of the report month. The count reflects standing on that day alone. The same grouping into PHP 8 or newer, PHP 7 or older, and undeclared is used every issue.
How it is computed
Counted from the author-declared "requires PHP" field, grouped into PHP 8 or newer and PHP 7 or older. Plugins leaving the field unset are reported as undeclared rather than assigned a version.
How to read it
Plugins are grouped into PHP 8 or newer and PHP 7 or older, based on the author-declared field on each listing. Read it beside old PHP, no updates to see a low declared PHP floor lined up with a lack of recent releases. Read it beside WordPress version adoption, the other measure built on a declared field rather than a verified one. A large undeclared group means many plugins have not set the field, not that they require an old PHP version. Reading the undeclared share beside the PHP 7 and PHP 8 shares shows how much of the directory has stated a floor.
What it is not
This measure does not confirm that a plugin actually requires, or works with, the PHP version it declares. The field is set by the plugin author and is not independently verified. A plugin leaving the field unset is reported as undeclared, not assigned by default to either group. It is not a measure of a plugin's actual code, only of what its listing states. It also does not say how recently the field was last changed by the author.
Related measures
Old PHP, no updates, Plugin support for WordPress versions, Plugins by install size