Remove Duplicate Lines

Remove duplicate lines from any text instantly. Free online tool, client-side only, your data stays private.

How to Remove Duplicate Lines

Removing duplicate lines from a large text file, email list, or dataset can be tedious. This tool allows you to instantly clean your data with several customizable options:

  • Case Sensitive: If disabled, "Apple" and "apple" are treated as duplicates.
  • Trim Whitespace: If enabled, leading and trailing spaces are ignored, meaning " Word" and "Word " are treated as duplicates.
  • Keep Last: By default, the first occurrence of a duplicate line is kept. Toggle this to keep the last occurrence instead.
  • Sort: Alphabetically sort the resulting unique lines.

Frequently Asked Questions

What are common use cases for removing duplicate lines?

Common use cases include cleaning up email subscriber lists before sending a campaign, deduplicating SEO keyword lists, consolidating server log files to find unique errors, and organizing spreadsheet data exports.

Does this tool store my text data?

No, this tool processes all your text locally in your browser using JavaScript. None of your data is ever uploaded or stored on our servers, ensuring complete privacy.

Related Guides

For more detailed methods and command-line alternatives, read our Guide on Removing Duplicate Lines.