Remove Duplicate Lines
Remove duplicate lines from your text. Choose to keep the first or last occurrence, or remove all duplicated lines entirely.
How It Works
The Remove Duplicate Lines tool scans your text line by line and identifies repeated entries. You can configure it to keep only the first occurrence of each duplicate, the last occurrence, or remove all lines that appear more than once.
Additional options let you control how duplicates are detected. Enable case-sensitive mode to treat "Hello" and "hello" as different lines, or disable it to treat them as identical. The trim whitespace option strips leading and trailing spaces before comparison, so lines that differ only in whitespace are considered duplicates.
This tool is ideal for cleaning up lists of email addresses, URLs, log entries, CSV rows, or any dataset where repeated lines need to be eliminated. All processing is performed entirely in your browser using JavaScript, so your data never leaves your device.
- Three duplicate-handling modes: keep first, keep last, or remove all
- Optional case-insensitive comparison
- Optional whitespace trimming for flexible matching
- Real-time statistics showing total, unique, and removed line counts