About this duplicate line remover
Remove repeated lines while preserving their first occurrence. Lines are compared exactly, including case and spaces. The first occurrence of each distinct line is kept. Work directly with your own text in this browser without signing in or uploading a document. Review the result before copying it into another application, and use Reset to clear the workspace when you are finished. The examples below show the exact behavior to expect, while the limitations explain cases where another workflow may be more suitable.
How it works
Lines are compared exactly, including case and spaces. The first occurrence of each distinct line is kept.
Try these examples
red blue red
red blue
A a A
A a
Limitations & privacy
Case and leading or trailing spaces matter. CRLF and CR line endings are normalized to LF; empty lines are deduplicated too. Maximum text input: 100,000 UTF-16 units.
Inputs and results stay in this browser. Only tool identifiers are stored for your recently used tools. You can clear that history from the directory.
A few good questions
How does this tool handle my input?
Lines are compared exactly, including case and spaces. The first occurrence of each distinct line is kept.
Does my text leave this browser?
No. Processing runs locally; tool input and results are not uploaded or included in analytics.
What should I check before using the result?
Case and leading or trailing spaces matter. CRLF and CR line endings are normalized to LF; empty lines are deduplicated too.
Updated September 19, 2026