With the release of WordPress 6.2, the core development team has made significant improvements in performance and the way they work. The new processes now identify and address issues as they arise during development, preventing them from being included in the final release.
Two key improvements that have enabled this change are:
- Introduction of a performance lead role
- Implementation of automated benchmarking
These enhancements have made performance an integral part of WordPress development.
In the previous release, WordPress 6.1, performance regressions (a decrease in performance resulting from improvements) were a major issue. Although the team fixed the most significant performance regression and implemented multiple enhancements, overall site performance was still affected by other changes that degraded performance.
To avoid such issues in the future, the development process for WordPress 6.2 included a new performance lead role. This role coordinated between development teams, who were responsible for performance improvements in their projects. The performance lead enabled closer collaboration and support between contributors, ensuring better representation of performance in the development process.
To address the inability to manually test every change for its impact on performance, WordPress introduced automated benchmarking for all changes. This approach measures the effect of each change, helping to identify performance bottlenecks before they make it into the final release.
Automated testing now takes place at each core commit in GitHub, measuring WordPress performance on both block and classic themes. Server timing metrics are also collected using the latest version of PHP.
The result of these changes is a substantial improvement in performance metrics. WordPress 6.2 loads 14-18% faster overall for block themes and 2-5% faster for classic themes (measured via Largest Contentful Paint). Server-side performance (measured via Time to First Byte) has seen a major boost, with a 17-23% increase for block themes and 3-5% for classic themes.
The development teams are currently working on standardizing the tools used for performance measurements, ensuring consistency across all teams.
With these improvements, WordPress has successfully integrated performance into its development process, catching up to other content management systems and making a significant impact on its performance capabilities.