How to keep Interaction to Next Paint under 200 ms
Interaction to Next Paint should be under 200 milliseconds. It measures how fast the page responds visually after a tap, click or key press, and long JavaScript tasks are the main cause of slow scores. Break up long tasks, defer scripts you do not need now and reduce third-party tags.
By ratemysite.ai editorial team. Updated .
How do you fix it?
- Record an interaction in the Chrome DevTools Performance panel and look for tasks longer than 50 ms on the main thread.
- Break long tasks into smaller chunks, and yield to the browser between them with setTimeout or scheduler.yield().
- Defer or lazy-load scripts that are not needed for the first interaction, and remove unused libraries.
- Audit third-party tags such as chat widgets, ads and trackers, and remove those you do not need.
- Re-run the audit and confirm the INP check passes.
What is Interaction to Next Paint?
INP is a Core Web Vitals metric that reports the longest delay between a user action, such as a tap, and the next time the screen updates. A score of 200 ms or less at the 75th percentile is good, while over 500 ms is poor. Slow responses make a site feel stuck, and visitors often tap again, which can trigger the action twice.
What makes interactions slow?
The main thread of the browser can do only one job at a time. If it is busy running a long script, a tap must wait. The usual causes are large JavaScript bundles, heavy event handlers, big DOM trees with several thousand nodes, and third-party scripts. Split code so each route loads only what it needs, move expensive work out of click handlers, and keep the DOM small. Measure on a mid-range phone, not a fast laptop.
How much does this check matter?
- This check is worth about 2.7% of the overall score.
- A finished report is reused for 24 hours before you can re-analyze it.
- Each page is fetched with a timeout of 10 seconds, and HTML larger than 2 MB is not audited.
What else do people ask?
- What replaced First Input Delay?
- INP replaced FID as a Core Web Vital in March 2024. It looks at all interactions during a visit, not only the first one.
- Can I test INP in the lab?
- Lab tools approximate it with Total Blocking Time. Real INP comes from field data, so use the Chrome UX Report or real-user monitoring.