P0Issue #70
Interaction to Next Paint (INP)
❓ What does it mean?
❓ What does it mean?
Interaction to Next Paint (INP) is a Core Web Vital metric introduced by Google.
It measures how quickly a webpage responds to user interactions (like clicks, taps, or key presses) and shows the next visible update (paint) on the screen.
Good INP: Below 200 ms (fast, smooth response).
Needs improvement: Between 200–500 ms.
Poor INP: Above 500 ms (laggy, frustrating).
🚨 Why is it important for SEO?
🚨 Why is this a problem for SEO?
User experience → If a page takes too long to react to clicks or taps, users feel it’s “slow” or “broken.”
Bounce rate increase → Delays frustrate visitors, leading to drop-offs.
Ranking factor → Since Core Web Vitals are part of Google’s ranking signals, poor INP can hurt visibility.
Conversion loss → A slow “Add to Cart” button, for example, directly impacts sales.
✅ How to Fix It
✅ Best Practices to Fix INP
Minimize JavaScript execution time → Break up long tasks into smaller chunks.
Use async/defer for non-critical scripts.
Avoid heavy re-renders in frameworks like React/Next.js.
Preload key resources (fonts, scripts, above-the-fold assets).
Use requestIdleCallback or setTimeout for non-urgent work.
Optimize event handlers (debounce/throttle expensive functions).
❌ Bad Example
📌 Example
❌ Bad (High INP – Slow Interaction):
<button onclick="heavyFunction()">Add to Cart</button>
<script>
function heavyFunction() {
// Long blocking task
for (let i = 0; i < 1000000000; i++) {}
document.body.style.background = "yellow";
}
</script>
When the button is clicked, the UI freezes before painting the update.
INP could be 800ms+.
✅ Good Example
✅ Good (Low INP – Optimized):
<button onclick="optimizedFunction()">Add to Cart</button>
<script>
function optimizedFunction() {
// Yield control to browser, update paint faster
setTimeout(() => {
document.body.style.background = "yellow";
}, 0);
}
</script>
Interaction response is immediate.
INP likely under 200ms.
⚡ Result
⚡ SEO & UX Impact of Fixing
Better Core Web Vitals score → Higher Google ranking.
Improved user trust (site feels fast and responsive).
Reduced bounce rate and better conversion rates.