CSS Selector Tester

Test CSS selectors against HTML code with comprehensive live highlighting, specificity analysis, and performance metrics for debugging CSS and learning advanced selector techniques. This development tool provides selector testing, real-time highlighting, specificity calculation, selector validation, and comprehensive examples with performance analysis. Essential for debugging CSS, learning advanced selectors, optimizing stylesheet performance, and understanding CSS selector behavior through interactive testing and educational resources.
Live Highlighting Specificity Analysis Performance Metrics Selector Validation
Quick Examples 
BASIC: .class #id
COMPLEX: div > p:nth-child(2)
ATTRIBUTE: [data-value="test"]
CSS Selector
Enter any valid CSS selector to test against the HTML
Selector Examples
HTML Templates
Export Results
Selection Results
Matches
0
Specificity
0,0,0,0
Selector Type
-
Performance
-
Current Selector: -
HTML Code
Live Preview with Highlighting
Matched Elements Details
Ready to Test CSS Selectors

Enter HTML code and CSS selectors to see live highlighting and detailed analysis of matched elements.

Features:
Live Element Highlighting
Specificity Calculation
Performance Analysis
Selector Examples

Help & Related Tools

Everything you need to know

FAQ Frequently Asked Questions

Can I test complex CSS selectors with pseudo-classes?
Yes, the tool typically supports advanced selectors including pseudo-classes (:hover, :nth-child), pseudo-elements (::before, ::after), attribute selectors, and complex combinators for comprehensive selector testing.
Does the tool show selector specificity calculations?
Yes, most tools display specificity values (0,0,0,0 format) helping you understand why certain styles might not apply and how to write selectors that properly override existing styles.
Can I see which elements are matched by my selectors?
Yes, matched elements are typically highlighted in the HTML preview, making it easy to verify that your selectors target the intended elements and understand selector scope and reach.
Is this helpful for debugging CSS issues?
Extremely helpful! Test why selectors aren't working, understand specificity conflicts, validate complex selector logic, and learn advanced CSS selector techniques through experimentation.
Can I learn advanced CSS selector techniques?
Yes, the tool is excellent for learning CSS selectors through experimentation. Try different selector patterns, see immediate results, and understand how various selector types work in practice.

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