Remove Duplicate Lines

Remove duplicate lines is a text tool that takes multiline input and removes lines that appear more than once. You can choose case-sensitive or case-insensitive comparison, whether to trim whitespace before comparing, and whether to keep the first or last occurrence of each unique line. The result can preserve original order or be sorted alphabetically.

A highlight mode lets you see duplicates in a different color without removing them. The tool shows total lines, unique lines, and duplicates removed. All processing runs in your browser.

Paste your multiline text into the input area. Choose case-sensitive or case-insensitive comparison. Toggle trim whitespace if you want " foo " and "foo" to be treated as the same. Select keep first or keep last occurrence. Choose preserve order or sort. Click Process to remove duplicates.

For highlight mode, toggle the option to show duplicates in a different color instead of removing them. Use Copy to copy the result. Stats show total lines, unique lines, and duplicates removed.

Use this tool for cleaning log files, deduplicating word lists, removing repeated entries from CSV-like data, cleaning up merged configs, or preparing text for further processing. Combine with sort when you need a unique, alphabetized list. All processing is client-side — your data never leaves your device.