WordPress’ Performance team is proposing merging Performant Translations into core in time for the upcoming WordPress 6.5 release. After an in-depth performance analysis earlier this year revealed that translations can significantly impact server response times, the team discussed various solutions and landed on one that requires no configuration from users. More than 2,000 WordPress sites have tested it through the Performant Translations feature plugin, after it was released in August.

Performance Team contributor Pascal Birchler, who penned the proposal to merge the plugin into core, explained how it speeds up sites using translations:

Performant Translations is powered by a new, lightweight i18n library that is faster at loading binary MO files and uses less memory. It even supports loading multiple locales at the same time, which makes locale switching faster. In addition to that, it supports translations contained in PHP files, avoiding a binary file format and leveraging OPCache if available. If an MO translation file has a corresponding PHP file, the latter will be loaded instead, making things even faster and use even less memory.

Birchler also published some compelling benchmarks demonstrating the plugin’s ability to reduce memory usage and decrease load time:

The Performance team has opened a ticket for merging the plugin into WordPress 6.5. Core committer Felix Arntz marked it as a high priority for the next release “due to the significant estimated impact this will have for localized sites’ performance.” The improvements stand to have a positive impact on the majority of WordPress sites (more than 50%) that are using translations.

WordPress 6.5 is expected in late March 2024. Getting merged this early in the release cycle would give Performant Translations the time it needs to be more widely tested and ready to go. Users who don’t want to wait until next year to get these reported performance improvements can install the plugin in the meantime.

“The Performant Translations plugin will continue to be maintained even after a core merge to build on top of the core solution with a distinct additional feature,” Birchler said. “As is already the case today, the plugin will automatically convert any MO files to PHP files if a PHP file does not currently exist. This is useful for sites where translations are not coming from translate.wordpress.org or only exist locally on that server.”