`web-vitals`

Overview

Core Web Vitals

Other Web Vitals

Install and load the library

From npm

From a CDN

Usage

Basic usage

Report the value on every change

Report only the delta of changes

Send the results to an analytics endpoint

Send the results to Google Analytics

Using `analytics.js`

Using `gtag.js` (Universal Analytics)

Using `gtag.js` (Google Analytics 4)

Send the results to Google Tag Manager

Batch multiple reports together

Bundle versions

Which bundle is right for you?

How the polyfill works

API

Types:

`Metric`

`ReportHandler`

`FirstInputPolyfillEntry`

`FirstInputPolyfillCallback`

`NavigationTimingPolyfillEntry`

`WebVitalsGlobal`

Functions:

`getCLS()`

`getFCP()`

`getFID()`

`getLCP()`

`getTTFB()`

Browser Support

Limitations

Development

Building the code

Running the tests

Integrations

License