# Performance & web vitals

Monitor how fast your pages feel to real users. With the **Record web vitals** feature enabled, the JavaScript tag captures page performance metrics like LCP, FCP, and TTFB from every sampled page load.

## View web vitals

Open the **Web vitals** dashboard from [Metrics](https://rum.betterstack.com/team/0/dashboards ";_blank"). The dashboard is created automatically for every application and charts the average alongside the p50, p90, p95, and p99 percentiles for each metric:

- **Time to first byte:** Full time to the first byte, including DNS, TCP, TLS, and server time.
- **HTTP request time to first byte:** Server time only, from sending the request to the first byte.
- **First contentful paint:** Time until the first content renders.
- **Largest contentful paint:** Time until the largest element renders.
- **JavaScript used heap size:** JS memory usage. A steadily growing baseline is the signature of a memory leak.
- **User agent specific memory:** Total browser memory for your site, plus a breakdown by JavaScript, DOM, and shared memory. Requires cross-origin isolation.

![Web vitals dashboard](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/e26feabf-48c9-4ad9-e1fb-48ccae9c3700/orig =3656x1502)

Focus on a single page with the **URL** filter at the top of the dashboard. It's a regular dashboard: change time ranges, add charts, or customize a copy.

## Chart web vitals your way

The web vitals are available as metrics on your application, with percentile aggregations like `p50`, `p90`, `p95`, and `p99`. Create your own charts in [Metrics](https://rum.betterstack.com/team/0/dashboards ";_blank") to:

- Track p95 Largest Contentful Paint per page.
- Compare performance across releases or environments.
- Alert on performance regressions with [chart alerts](https://betterstack.com/docs/logs/dashboards/alerts/).

## Performance in context

Performance data connects to the rest of real user monitoring:

- **Sessions:** Open a [session](https://betterstack.com/docs/rum/using-the-product/session-replays/) to see the pageload timeline of a specific visit, including backend spans when your backend is traced with Better Stack.
- **Slow page investigation:** Filter sessions by page with the search bar, then watch the replay to see what the user experienced.

## Next steps

- [Website visits](https://betterstack.com/docs/rum/using-the-product/website-visits/): traffic and engagement metrics.
- [Session replays](https://betterstack.com/docs/rum/using-the-product/session-replays/): watch what real users experienced.