# Check Core Web Vitals on mobile for documentation pages

**Use case:** 

Lighthouse Performance score and the lab Core Web Vitals (Largest Contentful Paint, Total Blocking Time, Cumulative Layout Shift) on a phone profile for three public documentation pages, with the biggest time savings and a link to the full report of each page. Replace the addresses with your own pages to build a mobile speed table, then schedule it to watch the trend.

## Input

```json
{
  "startUrls": [
    "https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API",
    "https://docs.python.org/3/tutorial/index.html",
    "https://nodejs.org/en/learn"
  ],
  "formFactor": "mobile",
  "categories": [
    "performance"
  ],
  "saveHtmlReport": true,
  "maxItems": 0,
  "onlyNew": false,
  "stateName": "default",
  "notifyWhenEmpty": false,
  "requestIntervalMs": 1000
}
```

## Output

```json
{
  "url": {
    "label": "Page address as given (fragment removed)",
    "format": "string"
  },
  "formFactor": {
    "label": "mobile (phone screen, slow 4G, 4x slower CPU) or desktop (wide screen, fast connection)",
    "format": "string"
  },
  "firstContentfulPaintMs": {
    "label": "First Contentful Paint in ms (lab)",
    "format": "integer"
  },
  "largestContentfulPaintMs": {
    "label": "Largest Contentful Paint in ms (lab Core Web Vital)",
    "format": "integer"
  },
  "totalBlockingTimeMs": {
    "label": "Total Blocking Time in ms (lab stand-in for Interaction to Next Paint)",
    "format": "integer"
  },
  "cumulativeLayoutShift": {
    "label": "Cumulative Layout Shift (lab Core Web Vital, unitless, 3 decimals)",
    "format": "number"
  },
  "speedIndexMs": {
    "label": "Speed Index in ms",
    "format": "integer"
  },
  "timeToInteractiveMs": {
    "label": "Time to Interactive in ms",
    "format": "integer"
  },
  "serverResponseTimeMs": {
    "label": "Server response time of the page request in ms (TTFB)",
    "format": "integer"
  },
  "totalByteWeight": {
    "label": "Total transfer size of the page and everything it loaded, in bytes",
    "format": "integer"
  },
  "requestCount": {
    "label": "Number of network requests the page made",
    "format": "integer"
  }
}
```

## How it works

### 1. Sign up on Apify or log in

The Lighthouse Audit API: Core Web Vitals and Performance Scores Actor is ready to run with the inputs already set for "Check Core Web Vitals on mobile for documentation pages". [Sign up or log in](https://console.apify.com/create-task-from-example/YRXM7qYF3vajadKsf) and you'll land in Apify Console with a copy of this exact task.

### 2. Start the "Check Core Web Vitals on mobile for documentation pages" task

The Lighthouse Audit API: Core Web Vitals and Performance Scores Actor will start running based on the input automatically. You can also change all the input fields, like pages to audit, device, and more, to match your specific use case.

### 3. Receive the "Check Core Web Vitals on mobile for documentation pages" output

Monitor the progress in real time. You will be notified as soon as your dataset is complete and ready for review. Each result includes data such as page address as given (fragment removed), mobile (phone screen, slow 4g, 4x slower cpu) or desktop (wide screen, fast connection), first contentful paint in ms (lab), and more.

### 4. Integrate into your workflow

The final output is delivered in JSON, CSV, or Excel format, ready to be plugged into your workflow. You can also [run the "Check Core Web Vitals on mobile for documentation pages" task via API](https://apify.com/rowcraft/lighthouse-performance-audit.md).

## About this Actor

This example demonstrates how to use [Lighthouse Audit API: Core Web Vitals and Performance Scores](https://apify.com/rowcraft/lighthouse-performance-audit.md) with a specific input configuration. Visit the [Actor detail page](https://apify.com/rowcraft/lighthouse-performance-audit.md) to learn more, explore other use cases, and run it yourself.


## How to integrate an Actor?

This Task's input is already configured above. Use it as-is rather than inventing a new one.

Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run.

For full API examples (JavaScript, Python, CLI, MCP, OpenAPI), see this Task's Actor page: https://apify.com/rowcraft/lighthouse-performance-audit.md

Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`).