Remove Duplicate Lines

How to use Remove Duplicates

1. Paste a line-based list or choose a local .txt or .csv file.
2. Set case, trimming, empty-line, first-or-last, and optional sorting rules.
3. Check the removal metrics, then copy or download the retained lines.

Supported behavior

Remove Duplicate Lines finds repeated records while keeping control over what “same” means. Comparison is case-sensitive by default, surrounding whitespace is not trimmed, empty lines are ignored during duplicate detection, and the first occurrence is retained. You can instead compare without case, trim for comparison, include empty lines, or keep the last occurrence. Original line content and order remain unchanged unless you explicitly trim output or sort after deduplication; normalization used only as a comparison key does not silently rewrite a retained line. Results report original and final line counts, duplicates removed, unique lines, and how empty lines were handled. This makes the tool suitable for lists where spelling and presentation must be preserved even when matching is relaxed. Text and selected .txt or .csv files are processed locally in your browser and are never uploaded. The operation compares whole lines, not parsed CSV fields, so use CSV Duplicate Remover when quoted cells or key columns define equality.

• Equality is line-based and does not understand CSV quoting, columns, or record structure.
• Case-insensitive matching follows Unicode/browser casing and is not a locale-specific collation database.

Examples

                apple
banana
apple
pear
banana
              

                North
north
North
              

Common use cases

• Deduplicate a newline-separated list of identifiers.
• Keep the latest repeated configuration line by preserving last occurrences.
• Clean copied labels without changing their original capitalization.

Related tools

• Sort Lines
• Remove Blank Lines
• Remove CSV Duplicates

Last reviewed 2026-07-21