Remove Duplicate Lines
Deduplicate multiline text while keeping the original order. Optional case-insensitive mode, trimming, and keeping empty lines. 100% local in-browser.
Tip: Windows/Mac newlines are supported. Output uses \\n.
What is a duplicate line remover?
A duplicate line remover is a text cleanup tool that removes repeated lines from multiline text. This page uses a stable dedupe algorithm, which means the first occurrence is kept and the original order is preserved.
How to use
- Paste your multiline text into the input box.
- Choose options like Trim lines and Case-insensitive.
- Click Dedupe (or just type—output updates automatically).
- Copy or download the cleaned result.
Common use cases
- Cleaning keyword lists for SEO or ads.
- Removing repeated values from exported data or logs.
- Normalizing inputs before sorting or adding prefixes/suffixes.
FAQ
Does this tool upload my text?
No. Deduplication runs locally in your browser by default. Your text is processed on your device.
What does “stable dedupe” mean?
It keeps the first occurrence of each unique line and preserves the original order of the remaining lines.
Why do I get unexpected duplicates?
Hidden whitespace and letter casing can make lines look identical but compare differently. Try enabling Trim lines and/or Case-insensitive.