Remove Duplicate Lines
Strip repeated lines from a list, with options for case, whitespace, blanks and sorting.
How to use this tool
- Select your file, drag it onto the box above.
- Processing starts automatically — there is nothing to configure.
- Check the result panel, which shows the original size, the final size and the page count.
- Click Download to save it.
The first occurrence of each line is kept and later repeats are dropped, so the original order survives unless you ask for sorting. Comparison options change what counts as a duplicate without altering the output text.
The specification
| Keeps | The first occurrence of each line |
|---|---|
| Ignore spaces | Compares trimmed lines |
| Ignore case | Treats Apple and apple as the same |
| Remove blanks | Drops empty lines |
| Sort | Optional alphabetical ordering |
How it works
This tool runs entirely in your browser. There is no server involved, which means nothing you type or upload is transmitted, stored, or logged — and there are no usage limits, because there is nothing for us to ration.
You can confirm it yourself: open your browser's developer tools, select the Network tab, and use the tool. No request is made.
Who uses this
Cleaning email lists, keyword lists, URL lists, log files and any exported data with repeated rows.
Frequently asked questions
Which duplicate is kept?
The first. Later occurrences are removed, so the original ordering of unique lines is preserved.
Does it change the text itself?
Only if you enable trimming, which removes leading and trailing spaces from the output as well as from the comparison. Otherwise lines are kept exactly as written.
Is there a size limit?
Only your browser’s memory. Lists of tens of thousands of lines process instantly.
Are my files uploaded to a server?
No. Everything runs inside your browser on your own device. Your file is never transmitted and never stored by us. You can confirm this by opening your browser’s Network tab while you use the tool — you will see no upload request.
Is there a limit on how many files I can process?
No. There is no daily cap, no account, and no watermark. Because the work happens on your device rather than our servers, there is nothing for us to ration.
Is this tool really free?
Yes — no account, no trial, no watermark, and no cap on usage. It runs on your own device rather than our servers, so there is no cost for us to pass on.
Does it work on mobile?
Yes. The interface adapts to phone and tablet screens, and everything runs in the browser, so there is no app to install.
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Your files stay on your device. This tool runs entirely in your browser. No file is uploaded, transmitted, or stored. You can verify this by opening your browser's Network tab while using the tool.
Disclaimer. Specifications published by exam boards, governments and platforms change without notice. We verify and date every specification on this site, but you should always confirm against the official source before submitting an application. See our full disclaimer.