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Text Deduplicator

Remove duplicate lines from text with multiple modes. Keep first or last occurrence, or remove all duplicated lines entirely. Options for case sensitivity, whitespace trimming, occurrence counting, and empty line handling. Runs entirely in your browser — your data never leaves your machine.

text deduplication lines cleanup utility

Published May 31, 2026

All interactive tools run entirely in your browser. Your data never leaves your device.

How It Works

Paste text with duplicate lines and the tool removes them based on your chosen mode. Keep the first occurrence, the last occurrence, or remove all lines that appear more than once. View statistics about how many duplicates were found and removed.

Features

  • 3 modes: keep first, keep last, remove all duplicates
  • Case sensitivity: toggle case-sensitive or case-insensitive comparison
  • Trim whitespace: normalize leading/trailing spaces before comparing
  • Occurrence counts: optionally show how many times each line appeared
  • Ignore empty lines: skip blank lines during deduplication
  • Statistics: total lines, unique count, duplicate count, removed count
  • 5 examples: basic dedup, with counts, case insensitive, remove all, email dedup
  • Private: all computation runs in your browser — no data transmitted

Use Cases

  • Cleaning up log files with repeated entries
  • Deduplicating email lists or CSV data
  • Removing duplicate imports or dependencies
  • Cleaning up configuration lists
  • Finding unique values in repetitive data