Core Web Vitals
Google's set of three field-measured user experience metrics — LCP, INP and CLS — used as part of the page experience signals in ranking.
TechnicalINP
Interaction to Next Paint
A Core Web Vital measuring overall responsiveness as the latency of the worst (approximately) interaction on a page; good is 200 ms or less at p75.
In full
INP observes clicks, taps and key presses through the page's whole lifetime and reports a high-percentile latency, covering input delay, processing time and presentation delay. It replaced First Input Delay in March 2024 because FID measured only the first interaction and only its input delay, and therefore looked good on pages that were in practice sluggish. Common causes of poor INP are long JavaScript tasks, heavy event handlers, large DOM sizes and third-party scripts.
Example
A filter panel runs a 500 ms synchronous sort on every checkbox click; yielding to the main thread and debouncing brings INP under 200 ms.
Related terms
First Input Delay
The retired responsiveness Core Web Vital measuring only the delay before the browser began processing a page's first interaction…
Third-party scripts
Externally hosted JavaScript such as analytics, tag managers, consent tools, chat widgets and ad code, which are a leading cause of poor…
Hydration
Attaching client-side JavaScript behaviour to server-rendered HTML so a static page becomes interactive.
Chrome User Experience Report
Google's public dataset of real-user performance measurements from opted-in Chrome users, and the official source of Core Web Vitals…
Where to read more
- Interaction to Next Paint (INP) · Documentation · web.dev