the WebKit team has rolled out a notable change in the 26.2 beta with support for two major performance APIs. This update moves Safari significantly closer to full Core Web Vitals support.
At RUMvision, our Core Web Vitals monitoring is powered by Google’s official web-vitals.js library. This means any browser that supports a Core Web Vital or underlying APIs will automatically be tracked in RUMvision.
INP and LCP support in beta
In the 26.2 Beta release of November 4th, Safari added support for Largest Contentful Paint (LCP) metric as well as Event Timing API that allows Interaction to Next Paint (INP) tracking.
Why this matters
In short, Safari is now aligning with broader browser efforts to measure user-experience performance (not just page load, but responsiveness and paint metrics) in a standards-compatible way. Large part of Core Web Vitals (Cumulative Layout Shift metric excluded) will then be supported in all major browsers (Chrome, Edge, Firefox and Safari).
We wrote about why this matters in a blogpost covering INP support by Firefox when shipped in Firefox 144. But if you're using a RUM tool that is using Google's web-vitals library (like RUMvision does), you most likely don't need to do anything to get insights into metrics across other supporting browsers.
When it will ship in stable
While Apple hasn’t publicly committed to an exact date for Safari 26.2 stable release, we can infer based on recent patterns and publicly available info:
- The beta for Safari 26.2 (via macOS/iOS ecosystem) is already out (Nov 4, 2025) for developers.
- Industry coverage (e.g., iOS 26.2 / macOS 26.2) suggests the final stable release is expected in December 2025, likely early-to-mid December.
- So, a safe prediction would be mid-December 2025 for Safari 26.2 stable, barring major issues.
For interopability, you can check our Firefox blogpost with live baseline support badges.
Not yet tracking Core Web Vitals with detailed real user monitoring? Get started with RUMvision today!
