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Google · · 6 min read
INP is the vital most sites still fail
Interaction to Next Paint is the vital that catches heavy marketing sites. The causes are predictable and mostly fixable.
What happened
INP measures how quickly a page responds when someone taps or clicks, and it's now part of Core Web Vitals.
- Interaction to Next Paint replaced First Input Delay as a Core Web Vital.
- It measures responsiveness across the whole visit, not just the first interaction.
- Heavy third-party scripts and large hydration payloads are the common failure causes.
- Google has increased the granularity of performance reporting in Search Console for mobile and desktop separately.
- Modern frameworks are evolving to better handle the orchestration of complex interactions without blocking the main thread.
Why it matters
A sluggish page frustrates visitors long before it affects rankings.
- Slow interaction hurts conversion directly, well before it affects rankings.
- Marketing sites with several tag manager containers fail most often.
- Good INP scores are a proxy for a well-engineered site that respects user time.
- As search becomes more interactive, the technical performance of a page impacts how AI tools perceive its utility.
- Consistent performance across all Core Web Vitals is a baseline requirement for maintaining SEO visibility in competitive niches.
What to do about it
Most INP problems trace back to a few heavy scripts. Fix those first.
- Audit third-party scripts and remove anything without an owner.
- Defer non-critical work and break long tasks into smaller chunks.
- Measure field data in Search Console, not just lab scores.
- Minimise the main-thread work by optimising long-running JavaScript functions.
- Use the Chrome DevTools Performance tab to identify specific interactions that trigger high INP values.
- Consider moving non-essential tracking and marketing scripts to a server-side tag management solution.