puppeteer is a tools created by Google to control the chrome/Chromium browser by script. It is useful for automatic testing website, or use it to control a headless browser. To use puppeteer to capture screenshot of a site, do:

1. Install node.js
2. cd to a directory you like
3. install puppeteer by

   npm i puppeteer

4. write a Javascript code

   const puppeteer = require('puppeteer');
   
   (async () => {
     const browser = await puppeteer.launch();
     const page = await browser.newPage();
     await page.goto("https://www.google.com", {waitUntil: 'networkidle0'});
     //await page.waitForTimeout(1000)
     await page.screenshot({ path: 'example.png' });
   
     await browser.close();
   })();

   networkidle0 the code will wait 500ms after all network activity is done. If the site has some javascript animation, you might need to wait more by using the commentted out waitForTimeout code

5. run the code by using node. Assume the code name example.js. You do

    node example.js

   in the terminal.

6. It will take around 10 seconds, more or less depends on the complexity of the site, and you will see a file call example.png created by it.

Add defaultViewport in the code like:

  const browser = await puppeteer.launch({
	defaultViewport: {width: 1920, height: 1080}
  });