demo · v133

Coarsened renderTime

Load a cross-origin image without Timing-Allow-Origin, observe LCP entries, and watch renderTime come through anyway — coarsened to protect cross-origin info. Before Chrome 133 this number would have been 0.

LCP renderTime (ms)

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LCP loadTime (ms)

—

checking support…

the code

new PerformanceObserver((list) => {
  for (const e of list.getEntries()) {
    console.log(e.entryType, e.renderTime, e.loadTime, e.url);
  }
}).observe({ type: "largest-contentful-paint", buffered: true });

// Pre-133: cross-origin entries without TAO got renderTime = 0.
// 133+: renderTime is exposed, coarsened to ~8ms.

the code

see also