CSS Selector Tester - Test Selectors Against HTML Online
CSS Selector Tester
Test Any Selector Against Your Own HTML
Understanding CSS Selector Testing
Debugging Stylesheets
Verify a selector actually targets the elements you expect before shipping a CSS change.
Scraping & Automation
Test a selector against sample HTML before using it in a scraper or browser automation script.
Learning Selectors
Experiment with combinators, pseudo-classes, and attribute selectors to build an intuition for how they match.
Local Processing
Your HTML and selector never leave your browser — matching runs entirely client-side.
How Matching Works
This tool parses your pasted HTML into a document and runs the browser's native querySelectorAll() against it — the exact same matching engine used by JavaScript and CSS in a real browser. This means any valid CSS selector syntax works here, including complex combinators like ul > li:nth-child(2) or attribute selectors like [data-active="true"].
Key Takeaways
- Native Matching Engine: Uses the browser's real querySelectorAll, not a reimplementation.
- Full Selector Support: Combinators, pseudo-classes, and attribute selectors all work as expected.
- Client-Side Only: All matching happens locally in your browser — no data is ever sent to a server.