What CSS selectors are supported?

All standard CSS selectors are supported, including class selectors (.class), ID selectors (#id), element selectors (div, p), attribute selectors ([href]), pseudo-classes (:hover, :first-child, :nth-child()), combinators (> + ~), and complex combinations. It uses the browser's native querySelectorAll() engine, so anything valid in CSS works here.

Why would I use a CSS selector tester?

A CSS selector tester helps you verify your selectors target exactly the right elements before writing your stylesheet. It's especially useful when working with complex selectors, debugging unexpected CSS behavior, learning selector syntax, or quickly finding elements in a document structure.

Does my HTML get sent to a server?

No. Everything runs entirely in your browser using JavaScript. Your HTML is never sent to any server, which means it's safe to use with sensitive or proprietary markup.

What is querySelectorAll() and how does this tool use it?

querySelectorAll() is a native browser DOM API that finds all elements matching a CSS selector. This tool uses it under the hood to evaluate your selector against a hidden copy of your HTML. If your selector works in this tool, it will work in real-world code using querySelectorAll() or getElementById().

Can I test pseudo-class selectors like :hover or :focus?

Pseudo-classes that depend on user interaction (:hover, :focus, :active) cannot be statically evaluated because they require the element to be in that state. Structural pseudo-classes like :first-child, :nth-child(), :last-of-type, and :not() work perfectly.

CSS Developer Tool

Test CSS Selectors
In Real-Time

Paste your HTML, type a CSS selector, and instantly see which elements match — highlighted with match count and element preview. Supports all selector types.

⚡

Instant Results

See matches highlighted in real-time as you type — no button to click, no delay.

🎯

All Selector Types

Supports class, ID, attribute, pseudo-class, pseudo-element, combinators, and complex selectors.

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100% Private

Everything runs in your browser. Your HTML never leaves your machine — no servers, no tracking.

error

Invalid HTML

HTML

Error

Invalid selector

Invalid HTML

Uses browser-native querySelectorAll() — same as real CSS100% client-side · no data sent to server

Frequently Asked Questions

Everything you need to know about CSS Selector Tester.

Test CSS SelectorsIn Real-Time

Instant Results

All Selector Types

100% Private

Frequently Asked Questions

Test CSS Selectors
In Real-Time