Glossary › Performance & Core Web Vitals
Performance & Core Web Vitals
Interaction to Next Paint
Also: INP
How quickly a page responds to user input. Replaced FID in 2024. Target under 200ms.
// Bad: synchronous heavy work blocks main thread
button.addEventListener('click', () => {
const data = expensiveComputation(); // blocks 500 ms
renderTable(data);
});
// Good: yield to browser between chunks
button.addEventListener('click', async () => {
showSpinner();
// Schedule into idle time so the click handler finishes fast
await scheduler.yield?.() ?? new Promise(r => setTimeout(r));
const data = expensiveComputation();
renderTable(data);
hideSpinner();
});
Why Interaction to Next Paint Matters
Interaction to Next Paint is one of the signals search engines and AI assistants use to evaluate page quality and relevance. Sites that get this right consistently outrank competitors who treat it as an afterthought — especially in 2026, where AI-generated answers favor content with clean technical foundations.
Practically, Interaction to Next Paint shows up in three places:
- Crawlers and indexers use it to decide whether (and how) to include the page in the index.
- Ranking algorithms weight it alongside dozens of other signals when deciding position.
- AI assistants use it as a citation-quality signal when picking which sources to reference.
How to Check Interaction to Next Paint
The quickest way to see whether Interaction to Next Paint is set up correctly on your site:
- Run a free atlookup audit — it surfaces every relevant signal automatically across all pages.
- Cross-reference with Google Search Console for any related coverage warnings.
- For per-page deep dives, run Lighthouse on your top 10 pages.
60-second page-by-page report. Every signal scored, prioritized, ready to act on.
Start free auditCommon Mistakes
- Treating it as one-and-done. Most signals drift over time as themes update, plugins change, and content moves. Audit at least monthly.
- Fixing symptoms instead of templates. If 100 pages have the same issue, the template is the problem. Fix once at the source.
- Skipping verification after fixes. Cache layers, CDNs, and stale indexes mean "fixed" rarely means "done" until you re-crawl.
Frequently Asked Questions
What is Interaction to Next Paint?
How quickly a page responds to user input. Replaced FID in 2024. Target under 200ms. See the full definition above for examples and context.
Why does Interaction to Next Paint matter for SEO?
Interaction to Next Paint affects how search engines and AI assistants understand and rank pages. Sites that get interaction to next paint right consistently outrank competitors who treat it as an afterthought.
How do I check Interaction to Next Paint on my site?
Run a free atlookup audit — it surfaces every interaction to next paint issue automatically across all pages, with each finding traced to a measurable signal.
How long until fixing Interaction to Next Paint affects my rankings?
Technical fixes typically take 2-8 weeks to register in rankings, depending on crawl frequency. AI Overview citations can shift within days of structural changes.
Is Interaction to Next Paint important in 2026?
Yes. With AI search now answering 40%+ of queries directly, signals like interaction to next paint are more important than ever — AI assistants weight them heavily when picking citations.