Web Vitals: Essential module for a healthy Nuxt

Web Vitals is an initiative by Google to provide unified guidance for quality signals that are essential to delivering a great user experience on the web.

This module will gather those metrics on each page view, and send them to a provider using either Navigator.sendBeacon() or fetch()

# yarn
yarn add --dev @nuxtjs/web-vitals

# npm
npm install --save-dev @nuxtjs/web-vitals

Add @nuxtjs/web-vitals to the modules section of your nuxt.config.js

export default defineNuxtConfig({
  modules: [
    '@nuxtjs/web-vitals'
  ]
})

⚠️ If you are using Nuxt < v2.9 you have to install the module as a dependency (no --save-dev or --dev flags). If you are Nuxt 2.9+ (but not Nuxt 3) you should add the module to buildModules instead of modules.

export default defineNuxtConfig({
  webVitals: {
    // provider: '', // auto detectd
    debug: false,
    disabled: false
  }
})

Report WebVitals to GA

Create a GA property and get trackingID

Either provide GOOGLE_ANALYTICS_ID environement variable or set inside nuxt.config:

(Top level googleAnalytics.id is supported for backward compatibility as fallback)

export default defineNuxtConfig({
  webVitals: {
    ga: { id: 'UA-XXXXXXXX-X' }
  }
})

Behavior > Events > Overview > Event Category > Event Action

Report WebVitals to GTM

Create a GTM property and add the tag manager to your site.

export default defineNuxtConfig({
  webVitals: {
    gtm: {}
  }
})

Report WebVitals to Vercel

Works without configuration

Report WebVitals to Console

Output metrics to the console insead of sending them to a remote provider

export default defineNuxtConfig({
  webVitals: {
    provider: 'log',
    debug: true, // debug enable metrics reporting on dev environments
    disabled: false
  }
})

⚠️ this provider does not send WebVitals trough network, issues with navigator extensions can not be deteced with this method.

Report WebVitals to a custom api endpoint

export default defineNuxtConfig({
  webVitals: {
    provider: 'api',
    api: { url: '/api/web-vitals' }
    debug: true // debug enable metrics reporting on dev environments
  })

Example body:

export default defineNuxtConfig({
  href: 'http://localhost:3000/',
  name: 'LCP',
  value: 303.599,
  rating: 'good',
  delta: 303.599,
  entries: [
    {
      name: '',
      entryType: 'largest-contentful-paint',
      startTime: 303.599,
      duration: 0,
      size: 5698,
      renderTime: 303.599,
      loadTime: 0,
      firstAnimatedFrameTime: 0,
      id: '',
      url: ''
    }
  ],
  id: 'v3-1669725914225-9792921995831',
  navigationType: 'reload'
})

MIT