Cut the time your page is unresponsive

Reduce main-thread JavaScript work so taps register immediately.

1–2 hours

why this matters

While scripts run, the browser ignores taps and clicks. Visitors read that as a broken button and tap again, or leave.

1
Audit third-party tags
Chat widgets, heatmaps, ad scripts and A/B testing tools are usually the bulk of the problem. List them, delete the ones nobody looks at, and load the rest after interaction or on idle.
2
Defer everything non-critical
Add defer to your own scripts, and load analytics and widgets after the page is interactive.
```
window.addEventListener('load', () => {
  requestIdleCallback(() => import('./chat-widget.js'));
});
```
3
Split your bundle
Load only the code the current page needs and import the rest dynamically at the point of use.
```
const Chart = React.lazy(() => import('./Chart'));
```
4
Break up long tasks
Any single task over 50ms blocks input. Chunk heavy loops and yield to the browser between chunks.
```
await scheduler.yield?.() ?? new Promise((r) => setTimeout(r, 0));
```