Skip to content
seo-scripts

How to Use JavaScript to Automate SEO

By Jose Luis Hernando

Programming and automation are increasingly popular in SEO, and for good reason. The real benefit isn’t just saving time. It’s freeing yourself from repetitive work so you can spend more time thinking.

This article covers why JavaScript is worth learning for SEO, the main paths to start automating, and practical examples to get you going.

Why JavaScript for SEO?

A lot of great automation in SEO comes from Python. But JavaScript has unique advantages worth considering.

1. To audit JavaScript on websites

Your website almost certainly uses JavaScript, whether it’s a full framework like React or Next.js, or just analytics and consent scripts. Learning the language gives you a stronger foundation to understand how JS might be affecting organic performance.

2. To understand new web technologies

The web development ecosystem moves fast, and JavaScript is at the center of it. Learning it helps you understand technologies like service workers, edge rendering, and streaming SSR, all of which can directly affect SEO.

3. To use tools like Google Tag Manager

Tag management systems like Google Tag Manager use JavaScript to inject code into websites. Knowing the language means you can understand what those tags do, create custom ones, and debug problems when things break.

4. To build your own websites and experiments

One of the best things about learning JavaScript is that you can build websites as side projects or testing grounds for SEO experiments. There’s no better way to understand something than getting your hands dirty.

Paths to JavaScript SEO Automation

JavaScript now runs everywhere. For SEO automation, there are two classic environments and one alternative that deserves its own section:

  • In the browser (front-end)
  • On your computer or a server (back-end, using Node.js)
  • Inside Google Sheets (via Google Apps Script)

Browser-Based Automation

You don’t need to install anything to get started. Browsers already run JavaScript.

The Browser Console

The simplest entry point is your browser’s DevTools console. For example, you can make any website editable:

document.body.contentEditable = true

Useful for mocking up new content or headings to show clients.

Chrome Snippets

If you use Chrome, Snippets offer a more user-friendly way to save and run custom scripts. You can create, edit, and execute them right from DevTools.

For example, I built a Snippet that counts all crawlable links on a page and downloads the list as a CSV. You can grab the code from GitHub.

Chrome Extensions

Chrome extensions let you build reusable tools that run on specific pages. I’ve built a few, including the GSC Index Coverage Extractor and the Search Console Compare Overlay. They use the same JavaScript you already know, plus a few browser APIs for tabs, storage, and content injection.

For heavier automation, you’ll want Node.js.

Back-End Automation with Node.js

Node.js lets you run JavaScript on your computer without a browser. Once installed, you can write scripts that interact with APIs, scrape websites, process files, and much more.

If you need help getting started, I wrote a guide on how to install Node.js for SEO.

Here are the areas where I see SEO professionals getting the most value from Node.js.

Extracting Data from APIs

Collecting data from different sources is one of the most common SEO tasks. Since Node 18+, you can use the native fetch API without extra dependencies:

const getPageSpeedData = async (url) => {
  const endpoint = 'https://www.googleapis.com/pagespeedonline/v5/runPagespeed';
  const key = 'YOUR-GOOGLE-API-KEY';
  const response = await fetch(`${endpoint}?url=${url}&key=${key}`);
  const data = await response.json();
  console.log(data);
  return data;
};

getPageSpeedData('https://www.searchenginejournal.com/');

For a more complete example, check out this script that uses Google’s PageSpeed API to extract Core Web Vitals data in bulk.

Scraping Websites

For basic HTML scraping, Cheerio combined with fetch works well:

import * as cheerio from 'cheerio';

const getTitle = async (url) => {
  const response = await fetch(url);
  const html = await response.text();
  const $ = cheerio.load(html);
  const title = $('title').text();
  console.log(title);
  return title;
};

getTitle('https://www.searchenginejournal.com/');

If you need the fully rendered version of a page (after JavaScript execution), Playwright can launch a headless browser and interact with the DOM just like a real user. It’s the go-to tool for browser automation in 2026.

Processing CSV and JSON Files

The built-in fs module reads and writes files. For CSV, csv-parse and csv-stringify are lightweight and reliable:

import { readFileSync, writeFileSync } from 'node:fs';
import { parse } from 'csv-parse/sync';

const input = readFileSync('urls.csv', 'utf8');
const records = parse(input, { columns: true });
console.log(records); // Array of objects

Cloud Functions for Serverless Tasks

Cloud providers like Google Cloud Functions, AWS Lambda, and Cloudflare Workers let you run scripts on a schedule without managing a server.

A practical example: schedule a function that extracts Search Console data daily and stores it in BigQuery. No laptop needed, it just runs.

Google Apps Script as an Alternative Path

Google Apps Script is arguably the easiest way to start coding for SEO. It runs inside Google Sheets, Docs, and other workspace apps already part of most SEO workflows.

I recently wrote about how Claude Code transformed my Apps Script workflow. If you work with GSheets-based reporting, it’s worth a look.

There are great community projects to learn from, like Hannah Butler’s Search Console explorer sheet. Dave Sottimano also gave an excellent talk at Tech SEO Boost covering many ways to use Apps Script for SEO.

Final Thoughts

JavaScript remains one of the most popular programming languages in the world, and AI-assisted coding tools like Claude Code, Gemini, and ChatGPT Codex have made the barrier to entry lower than ever. Whether you write scripts from scratch or describe what you want in plain English, automating repetitive SEO work is now within reach for everyone.

This article is based on a piece I originally wrote for Search Engine Journal. It has been significantly updated with modern tooling and examples.

Have questions or want to share your own automation projects? Find me on 𝕏 @jlhernando or LinkedIn.