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Performance Metrics

更新于 写于 front end

Metrics Good Poor
TTFB (Time To First Byte)
FP (First Paint)
FCP (First Contentful Paint)
LCP (Largest Contentful Paint) < 2.5 sec > 4.0 sec
CLS (Cumulative Layout Shift) < 0.1 > 0.25
INP (Interaction to Next Paint) < 200 ms > 500 ms
TBT (Total Blocking Time)

Note:

  • First Meaningful Paint (FMP) is deprecated in Lighthouse 6.0. In practice FMP has been overly sensitive to small differences in the page load, leading to inconsistent (bimodal) results.
  • First Input Delay (FID) is no longer a Core Web Vital, and has been replaced by the Interaction to Next Paint (INP) metric.
  • Max Potential First Input Delay was deprecated in Lighthouse 6.0.
  • Time to Interactive (TTI) has proved overly sensitive to outlier network requests and long tasks, resulting in high variability in this metric.

See: