Remove Duplicate Lines from a List or CSV
Paste a list, or drop a .txt or .csv file, and download it back with every duplicate line removed. Nothing is sent anywhere.
Remove Duplicate Lines from a List or CSV
Drop your text or CSV file here
Up to 20MB per file. Stays on this device.
Nothing is sent anywhere. Turn off your Wi-Fi and this page still works — try it.
How it works
- Drop or choose a .txt or .csv file, or paste a list directly into the text box.
- Turn on “ignore case”, “ignore surrounding whitespace”, or “skip blank lines” if you need them — the preview and the counts update immediately.
- Review the count of duplicates removed and the preview, then download the result.
Frequently asked questions
Is my list or file sent anywhere?
No. Pasted text and uploaded files are both read entirely on your device — nothing is sent to a server. Turn off your Wi-Fi after the page loads and it still works.
How does it decide two lines are duplicates?
By exact text match, line by line — not a fuzzy or “looks similar” match. foo and foo (with a leading space) count as different lines unless you turn on “ignore surrounding whitespace”, and Apple and apple count as different unless you turn on “ignore case”. This is deliberate: silently treating visually different lines as identical would be a surprising thing for a dedup tool to do without being asked.
Does this work on a CSV file, not just a plain list?
Yes — each row of a CSV is compared as one line of text, so a row that exactly repeats (every column, in order) is removed the same way a repeated plain-text line is. The one case this does not specially parse is a quoted CSV field that itself contains a line break; a row like that is treated as more than one line, the same way a plain text editor would show it.
Which occurrence of a duplicate is kept?
The first one. Everything after the first occurrence of an exact-match duplicate is removed; the file’s original row order is otherwise preserved.
What happens to blank lines?
By default, blank lines are deduped like any other line — five blank lines in a row become one. Turn on “skip blank lines” to remove all of them from the output instead.
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