How to generate a Lighthouse report in puppeteer

Generating a Lighthouse report using Puppeteer involves launching a headless Chrome browser and running Lighthouse programmatically. Here’s how you can do it step-by-step:

Step-by-Step Guide to Generate a Lighthouse Report with Puppeteer

1. Install Puppeteer and Lighthouse:

   Ensure you have Puppeteer and Lighthouse installed as dependencies in your project:

   npm install puppeteer lighthouse
   

2. Write the Puppeteer Script:

   Create a script that launches Puppeteer, navigates to a URL, and generates a Lighthouse report.

   const puppeteer = require('puppeteer');
   const lighthouse = require('lighthouse');
   const { URL } = require('url');
   
   (async () => {
     const browser = await puppeteer.launch();
     const page = await browser.newPage();
   
     // URL to analyze with Lighthouse
     const url = 'https://example.com';
     
     // Launch Lighthouse and get the report
     const report = await lighthouse(url, {
       port: (new URL(browser.wsEndpoint())).port,
       output: 'json',
       logLevel: 'info',
     });
   
     // Output Lighthouse report
     console.log('Lighthouse report:', report.lhr);
   
     await browser.close();
   })();
   

   • Replace 'https://example.com' with the URL of the site you want to analyze.

3. Run the Script:

   Execute your Puppeteer script to launch a headless Chrome instance and generate the Lighthouse report:

   node lighthouse-report.js
   

4. Interpret the Lighthouse Report:

   The Lighthouse report (report.lhr) contains detailed information about performance, accessibility, SEO, and best practices for the specified URL.