LCP and INP are now Baseline Newly available as of December 12, 2025.

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Safari 26.2 now supports the Largest Contentful Paint (LCP) and Interaction to Next Paint (INP) APIs, making these Core Web Vitals metrics measurable across all major browsers for the first time. This cross-browser support enables more comprehensive performance monitoring through Real User Monitoring (RUM) tools, though Chrome User Experience Report (CrUX) will continue to only include Chrome data. Minor implementation differences exist between browsers, particularly in timing measurements, but the metrics are broadly interoperable. Cumulative Layout Shift (CLS) remains Chromium-only for now.

LCP and INP are now Baseline Newly available

Will data from other browsers feed Cr UX?

Are there any differences in the implementations?

What about browsers that don't support these APIs?