jsdom
jsdom is a pure JavaScript implementation of web standards, notably the WHATWG DOM and HTML standards, for use with Node.js. It simulates a browser environment in Node.js, allowing you to parse HTML, manipulate the DOM, and interact with web pages using the same APIs available in web browsers.
Key features for web scraping:
- Full DOM implementation Provides document.querySelector, document.querySelectorAll, and other standard DOM methods for traversing and manipulating parsed HTML.
- Browser-like environment Simulates window, document, navigator, and other browser globals, enabling code that was written for browsers to run in Node.js.
- JavaScript execution Can execute JavaScript embedded in HTML pages, including external scripts, making it possible to process pages that generate content dynamically (though much slower than a real browser).
- Standards-compliant parsing Uses the same HTML parsing algorithm as web browsers (the WHATWG HTML specification), ensuring accurate handling of malformed HTML.
- Cookie support Implements the tough-cookie library for cookie handling across requests.
For web scraping, jsdom is useful when you need more than simple CSS selector matching (what cheerio provides) but don't need a full browser. It's ideal for parsing complex HTML and running simple inline scripts without the overhead of Playwright or Puppeteer. However, for heavy JavaScript-rendered pages, a real browser automation tool is recommended.
Highlights
Example Use
```javascript const { JSDOM } = require('jsdom');
// Parse an HTML string const html = `
Product A
$10.99 <div class="product">
<h2>Product B</h2>
<span class="price">$24.99</span>
</div>
</body>
`;
const dom = new JSDOM(html); const document = dom.window.document;
// Use standard DOM APIs to extract data
const products = document.querySelectorAll('.product');
products.forEach(product => {
const name = product.querySelector('h2').textContent;
const price = product.querySelector('.price').textContent;
console.log(${name}: ${price});
});
// Fetch and parse a remote page JSDOM.fromURL('https://example.com').then(dom => { const title = dom.window.document.title; console.log('Page title:', title); }); ```