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CSS Duplicate Selector Finder

Find selectors that are declared more than once in the same stylesheet.

Processed in your browser

Your result will appear here as soon as you add some input.

How to use it

  1. 1Paste your input into the input box, or type it directly.
  2. 2Adjust the options if you need something other than the defaults.
  3. 3The result updates as you type.
  4. 4Copy the result to your clipboard or download it as a file.

About the CSS Duplicate Selector Finder

Repeating a selector is legal and sometimes deliberate - a later block deliberately overriding an earlier one, or a rule inside a media query. The point of the report is to let you confirm each repeat is intentional.

Unintentional duplicates are where "I changed the colour and nothing happened" comes from.

Questions people ask

Is your code uploaded to a server?

No. This tool runs entirely in your browser using standard web APIs, so your code never leaves your device. You can confirm it by opening your browser's network panel while the tool runs, or by disconnecting from the internet after the page has loaded.

Is it free, and do I need an account?

Yes, it is free, and there is no account, no sign-up and no watermark on the result. The project is funded by optional donations.