Duplicate Line Remover

Strip duplicate lines from any list with optional case-insensitive and trim modes.

Paste any list and remove duplicate lines instantly. Toggle case-insensitive matching, trim each line before comparing, and optionally show how many times each unique line appeared. Browser-only — your list never leaves your device.

Common use cases

  • Clean up an email mailing list before importing into Mailchimp or HubSpot
  • Deduplicate a shopping or to-do list copied from multiple sources
  • Find unique error messages in a verbose log file
  • Count how many times each item appears in a survey response export

Frequently asked questions

Does it preserve the order of first appearances?
Yes. The first occurrence of each line keeps its position; later duplicates are dropped.
What does 'case-insensitive' do?
When enabled, 'Apple', 'apple' and 'APPLE' are treated as the same line. The output keeps whichever variant appeared first.
Can I see counts?
Yes — toggle 'Show occurrence counts' and the output becomes a tab-separated count + line, ready to paste into a spreadsheet.

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