How can I use Puppeteer for SEO auditing?

Puppeteer is a headless browser from the Chrome team at Google. It provides a high-level API to control headless Chrome or Chromium over the DevTools Protocol and is useful for generating screenshots and PDFs of pages, crawling websites for SEO auditing, and automating form submissions, UI testing, keyboard inputs, etc.

You can use Puppeteer for SEO auditing by checking the site for SEO best practices, such as title and meta description length, header usage, alt attribute usage, etc. Here's a step-by-step guide on how you can use Puppeteer for SEO auditing.

Step 1: Install Puppeteer

To use Puppeteer, you need to have Node.js installed on your computer. If you don't have Node.js installed, you can download it from the official website. Once you've installed Node.js, you can install Puppeteer with the following command:

npm i puppeteer

Step 2: Create a new Puppeteer script

Create a new JavaScript file (let's call it seo-audit.js) and require Puppeteer at the top of the file.

const puppeteer = require('puppeteer');

Step 3: Launch Puppeteer and go to the site you want to audit

Next, you'll need to launch Puppeteer and navigate to the site you want to audit.

(async () => {
  const browser = await puppeteer.launch();
  const page = await browser.newPage();
  await page.goto('https://example.com');
})();

Step 4: Run SEO checks

You can now run various SEO checks on the site. For example, you might want to check the length of the title and meta description, the usage of headers, and the usage of the alt attribute on images.

(async () => {
  // ...

  // Check title length
  const title = await page.title();
  console.log(`Title: ${title}`);
  console.log(`Title length: ${title.length}`);

  // Check meta description length
  const metaDescription = await page.$eval(
    'meta[name="description"]',
    (element) => element.content
  );
  console.log(`Meta description: ${metaDescription}`);
  console.log(`Meta description length: ${metaDescription.length}`);

  // Check header usage
  const headers = await page.$$eval('h1, h2, h3, h4, h5, h6', (elements) =>
    elements.map((element) => ({
      tagName: element.tagName,
      text: element.innerText,
    }))
  );
  console.log(`Headers: ${JSON.stringify(headers, null, 2)}`);

  // Check alt attribute usage on images
  const images = await page.$$eval('img', (elements) =>
    elements.map((element) => ({
      src: element.src,
      alt: element.alt,
    }))
  );
  console.log(`Images: ${JSON.stringify(images, null, 2)}`);

  // ...

  await browser.close();
})();

Step 5: Run the script

Finally, you can run the script with the following command:

node seo-audit.js

This script will print out the title and meta description length, the usage of headers, and the usage of the alt attribute on images. You can add more checks based on the specific SEO best practices you're interested in.

Remember that this is a basic example of what Puppeteer can do. You can customize and expand this script to fit your specific needs. For instance, you could write the results to a file, or even build a web service that performs SEO audits on demand. Puppeteer is a powerful tool that can automate many browser tasks, making it a valuable tool for SEO auditing.