Remove duplicate rows from a CSV
Drop repeated rows in seconds. Match on every column or only the ones that identify a record, and keep the first copy of each.
- Nothing uploaded
- Instant results
- No account needed
Drop a CSV file hereUp to 10 MB · processed in this tab, never uploaded
Your result appears here as soon as you add a file.
How it works
Three steps, nothing to install- 01
Drop in a CSV, choose a file, or paste the text.
- 02
Pick the columns that identify a duplicate, or leave them all selected for exact matches.
- 03
Check the count of removed rows, then download the cleaned file.
Good to know
What the tool does, exactlyWhat counts as a duplicate
By default a row is a duplicate when every cell matches an earlier row exactly. Choose specific columns, such as an email address, to treat rows as the same record even when other fields differ. The first occurrence is always kept, in its original position.
Why near-duplicates slip through
“ana@northwind.io” and “ ANA@northwind.io ” look the same to a person but not to a computer. Turn on “Ignore case” and “Ignore extra spaces” to catch them, or run Trim whitespace first so the values themselves are fixed.
Private by design
The file is processed in your browser and never uploaded, so it’s safe for customer lists and financial exports.
Questions
About remove duplicatesWhich copy of a duplicate is kept?
The first one in the file. Later rows that match it are removed, and the order of everything else is unchanged.
Can I remove duplicates based on one column?
Yes. Untick the columns that should not be compared. For example, compare only “email” to keep one row per address.
Does it change the rows it keeps?
No. Ignore case and Ignore extra spaces only affect how rows are compared; the values in the downloaded file are exactly as they were.
Is there a file size limit?
Files up to 10 MB work comfortably in the browser. Nothing is uploaded, so the limit is your device’s memory rather than a server.
Keep going
All free toolsCleaning the same
files every week?
The free workspace saves each dataset, with undo and a full history. See features