demo · v136

LCP Debugger

Read all four "what happened before LCP" markers in one pane: activationStart, firstInteraction, userActivation, and the new entries that surface back/forward cache restores and prerender activations. Hit the buttons to mark the page as activated/interacted and watch the verdict update.

Note: some of these fields are still being added to PerformanceObserver entries in Chrome 136. Fields that are missing read as n/a instead of failing.

verdict

computed stats

navigation start (ms since UNIX)—

activationStart (prerender / restore)—

firstInteraction (synthetic)—

userActivation API state—

LCP entry startTime—

"warm" LCP (LCP − interaction)—

verdict

computed stats

see also