Making Sense of the Performance Extensibility API
August 4, 2025

Google Chrome recently introduced the Performance Extensibility API, a means of putting your code front-and-centre in Chrome’s Performance panel. Their own documentation is somewhat dry and doesn’t really state the benefits or outcomes very clearly, so I spent a couple of hours looking into it and here are the key takeaways.
Source: Making Sense of the Performance Extensibility API – CSS Wizardry
While it’s Chrome only (for now ?), the Performance Extensibility API provides ways for developers to get more fine grained understanding of the performance of a page. Harry Robert provides the details.