Compute CSS selector specificity (a,b,c scores) and settle override battles with math. Prove #id beats .class chains — local calculation, free, no signup.
Content reviewed October 2026 · About Toolzum
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IDs, classes/attributes, elements counted as (a,b,c): #nav .item a scores (1,1,1) beating (0,3,0). Higher leftmost number always wins regardless of right side.
A higher-specificity rule wins silently — compute both selectors here. !important beats everything but creates debt; raise specificity properly instead.
:not() adds its argument's specificity; :is() takes its most specific argument; :where() adds zero. Modern selectors follow these exact rules.
No — calculation runs locally in your browser. Code never leaves your device.
CSS Formatter
Organizes CSS stylesheets with consistent indentation, property grouping, and selector formatting for maintainable styles.
CSS Validator
Validate CSS syntax — unclosed braces, bad properties, bad values — with line numbers. Catch the missing } breaking layouts — local validation, free, no signup.