PERFORMANCE
INP explained: how to make your site feel instant
Interaction to Next Paint replaced FID as a Core Web Vital. What INP measures and how to fix slow clicks, taps and typing.
By VISIBI Performance team·Reviewed by Saeed Ak, Co-founder & CTO·Updated 29 September 2026·7 min read
QUICK ANSWER
Interaction to Next Paint replaced FID as a Core Web Vital. What INP measures and how to fix slow clicks, taps and typing.
KEY TAKEAWAYS
✓INP measures how quickly the page responds to user interactions.
✓Good INP is 200 milliseconds or less.
✓Heavy JavaScript and third-party scripts are the usual culprits.
What INP measures
INP looks at the latency of interactions — clicks, taps and key presses — throughout a visit and reports one of the slowest. It replaced First Input Delay as a Core Web Vital in 2024.
RELATED GUIDEIs Cloudflare worth it? 9 benefits for ecommerce and business websites → More sales from the same traffic?Research-led CRO, built and shipped by our developers.Get a free CRO audit →Common causes
- Long JavaScript tasks on the main thread
- Heavy third-party tags
- Large DOM sizes
- Expensive re-renders in frameworks
- Synchronous work in event handlers
Fixes
- Break up long tasks and yield to the main thread
- Defer non-critical third-party scripts
- Reduce DOM size
- Optimise framework rendering
- Show immediate visual feedback on interaction
Common mistakes to avoid
✕Only testing the homepage
✕Optimising lab scores instead of real-user data
✕Adding third-party scripts without a performance budget
✕Leaving load testing until the week before peak
HOW VISIBI CAN HELP
How we help with performance
01MeasureReal-user Core Web Vitals and load tests on key journeys.
02Fix in codeOur developers fix the root cause, not just the symptom.
03Protect peaksAutoscaling, caching and war-room cover for big days.
04MonitorAlerts on speed and checkout regressions with VISIBI Guard.
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Frequently asked questions
What is a good INP?
200 ms or less at the 75th percentile.
How do I find slow interactions?
Use Chrome DevTools Performance panel and real-user monitoring.
Does INP affect conversion?
Slow interactions frustrate shoppers, especially on filters and add-to-basket.
SA
Reviewed by Saeed Ak · Co-founder & CTO25 years engineering high-traffic ecommerce, cloud and security platforms. Written by the VISIBI Performance team.Meet the team →
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