cheerio

Cheerio provides a jQuery-like API for server-side HTML manipulation that's genuinely convenient for scraping and templating tasks. The selector syntax feels natural if you know jQuery, and performance is solid for most use cases. However, from a security standpoint, you need to be thoughtful about how you use it.

The library doesn't sanitize HTML by default—it's a parser, not a sanitizer. If you're parsing untrusted HTML and then rendering it, you're responsible for XSS prevention. Cheerio will happily parse and preserve malicious scripts. I've seen teams assume it provides some protection, which it doesn't. You'll need additional tools like DOMPurify or a dedicated sanitization library for user-generated content.

Input validation is on you entirely. The error messages when parsing malformed HTML aren't particularly informative, and it tends to be permissive rather than strict. This flexibility is useful for scraping wild web content, but makes it easy to miss issues. Dependency-wise, it pulls in htmlparser2 and other parse5-related packages, so you're inheriting their CVE surface. Overall useful but demands security-conscious implementation.

Cheerio is my go-to for server-side HTML parsing and manipulation. It implements a jQuery-like API which makes it instantly familiar, and crucially, it's synchronous - no dealing with browser headless complexity when you just need to scrape or transform markup. The parsing is fast and memory-efficient for typical web pages, though I've seen it struggle with multi-megabyte HTML documents where streaming would be better.

The library is stateless and doesn't manage connections or resources beyond the parsed DOM tree, which is exactly what you want. Error handling is straightforward - malformed HTML gets parsed permissively by default (thanks to htmlparser2 underneath), and selectors that don't match simply return empty collections rather than throwing. One gotcha: there are no built-in timeouts or resource limits, so you need to handle input validation yourself to prevent parsing malicious or pathologically large documents.

The biggest operational win is predictability - performance is deterministic based on input size, no weird async behavior or connection pool exhaustion. Logs are minimal (basically non-existent), so instrument your own timing if you need observability. Version upgrades have been smooth in my experience, with breaking changes well-documented.

Cheerio has been my go-to for web scraping and HTML manipulation in Node.js for years. The learning curve is essentially zero if you know jQuery - you can start with `$('.selector')` and be productive immediately. The API is intuitive and the documentation provides clear examples for common operations like traversing, selecting, and modifying DOM elements.

What I appreciate most is how straightforward debugging is. The library doesn't hide complexity - when selectors fail, you get predictable empty results rather than cryptic errors. Error messages are helpful when you do encounter issues, like malformed HTML or incorrect method usage. Performance is excellent even with large HTML documents, and memory usage stays reasonable.

The ecosystem support is solid. Stack Overflow has tons of answers, and most jQuery solutions translate directly to Cheerio. Common tasks like extracting data from tables, finding links, or cleaning up scraped content are all simple one-liners. The only gotcha is remembering it's server-side only - no JavaScript execution or browser events.