```yaml
product: AlterLab
title: "BeautifulSoup — Web Scraping Glossary | AlterLab"
comparison_context: "AlterLab is an alternative to Firecrawl, ScrapingBee, and Bright Data."
source_url: https://alterlab.io/glossary/beautifulsoup
```

tool

# BeautifulSoup

A Python library for parsing HTML and XML and navigating the parse tree using CSS selectors or tag methods.

BeautifulSoup is a Python library for parsing HTML and XML documents and navigating the resulting parse tree. It accepts HTML from any source — an HTTP response, a file, a string — and exposes the parsed document through an intuitive API: find elements by tag name (`soup.find('div')`), by class (`soup.find_all('p', class_='description')`), by CSS selector (`soup.select('.price')`), or by attribute (`soup.find('a', href=True)`).

BeautifulSoup works with multiple underlying parsers. The built-in `html.parser` is included with Python and handles most HTML correctly. For faster parsing of large documents, `lxml` provides a C-backed HTML and XML parser. For extremely lenient parsing of malformed HTML, `html5lib` produces a browser-compatible parse tree regardless of how broken the markup is.

The key limitation of BeautifulSoup is that it operates on static HTML — it does not execute JavaScript. For JavaScript-rendered pages, the HTML must first be rendered by a browser (Playwright, Puppeteer, or a scraping API with JavaScript rendering enabled). AlterLab's API returns the post-render HTML, which can then be parsed with BeautifulSoup for structured extraction.

### What is BeautifulSoup?

A Python library for parsing HTML and XML and navigating the parse tree using CSS selectors or tag methods.

### How does AlterLab handle BeautifulSoup?

The key limitation of BeautifulSoup is that it operates on static HTML — it does not execute JavaScript. For JavaScript-rendered pages, the HTML must first be rendered by a browser (Playwright, Puppeteer, or a scraping API with JavaScript rendering enabled). AlterLab's API returns the post-render HTML, which can then be parsed with BeautifulSoup for structured extraction.

## Examples

```
from bs4 import BeautifulSoup

# Parse AlterLab's HTML response
soup = BeautifulSoup(response['html'], 'lxml')

# Extract by CSS selector
prices = soup.select('div.price > span.amount')
for price in prices:
    print(price.text.strip())
```

## Related Terms

[ScrapyAn open-source Python framework for large-scale web crawling and scraping with async request scheduling, deduplication, and output pipelines.](https://alterlab.io/glossary/scrapy)[CSS SelectorA pattern used to match HTML elements by tag, class, ID, or attribute, used in web scraping to extract specific nodes from parsed HTML.](https://alterlab.io/glossary/css-selector)[XPathXML Path Language — a query syntax for selecting nodes in HTML or XML using path expressions, more expressive than CSS selectors for complex traversals.](https://alterlab.io/glossary/xpath)[Data ExtractionThe process of identifying and pulling specific fields from raw web content, converting unstructured HTML into typed JSON records.](https://alterlab.io/glossary/data-extraction)[JavaScript RenderingThe process of executing a page's JavaScript in a browser engine before extracting content, required for React, Vue, and Angular SPAs.](https://alterlab.io/glossary/javascript-rendering)

## Extract BeautifulSoup data from any website

AlterLab returns clean, structured data from any public URL — no scraper infrastructure needed. Start free, no credit card required.

[View API docs](https://alterlab.io/docs/api/rest)

[Back to Glossary](https://alterlab.io/glossary)