Duplicate Line Remover Online — Deduplicate Text Lines
Remove duplicate text lines online while preserving the first occurrence and original order.
About this tool
Line endings are normalized, then JavaScript Set semantics retain the first exact occurrence of every line, including one blank line.
How to use
- Enter or select the required input.
- Run the tool with the intended options.
- Review the result before using or downloading it.
Features
- First-occurrence order preserved.
- Exact line matching.
- Local processing.
Common use cases
- Clean exported lists.
- Deduplicate IDs.
- Remove repeated log values.
Common issues and tips
- Comparison is case-sensitive.
- Whitespace makes otherwise similar lines different.
Privacy
Processing runs locally in your browser. Input is not uploaded to Tools12345.
Frequently asked questions
Is order preserved?
Yes, the first occurrence remains.
Is matching case-sensitive?
Yes.
Are lines trimmed?
No, use List Cleaner for trimming.