WP PHP Translation Files

Use plain PHP files for WordPress translations instead of .mo files.

The WordPress i18n system uses gettext, which operates with source .po (Portable Object) files and binary .mo (Machine Object) files for storing and loading translations. is not trivial. With this solution, translations will instead be stored in plain .php files returning an associate array of translation strings. Whenever a .php file is available, it will be preferred over the .mo file, which is still used as a fallback.

Ideally, the .php files will be served directly from translate.wordpress.org. For this proof of concept, the .php files are created automatically after translation updates and also on demand when loading .mo files.

Format

<?php
return [
    'translation-revision-date' => '+0000',
    'generator' => 'WordPress/6.3-alpha-55629',
    'messages' => [
        'Foo' => ['Bar'],
        'Bar' => ['Baz'],
        '1 Dragon' => ['1 Dragon', '2 Dragons'],
    ]
];

Performance

Nothing is faster in PHP than loading and executing another PHP file. JSON, INI, or XML would all be much slower.

Some initial measurements taken for a typical frontend request:

In short, this reduces load time by ~10% and memory usage by ~7% for localized WordPress sites.