How to use the Remove Duplicate Rows tool
- Choose an .xlsx, .csv or .tsv file and pick the sheet if there are several.
- Say whether the first row is a header. A header row is never removed.
- Tick the columns that identify a duplicate, or leave them all unticked to compare entire rows. Choose whether case and outer spaces matter.
- Press Remove duplicates, check how many rows were removed and download the cleaned file.
Worked example: a contact list with repeated emails
contacts.csv has a header row (Name, Email, City) and 10 contacts. Three emails appear twice, for example [email protected] in row 2 and [email protected] with a leading space in row 5. Tick only the Email column and keep the default settings.
- The result reads 3 duplicate rows removed.
- The note says 10 data rows before, 7 after, and lists the removed sheet rows: 5, 8, 11.
- The first copy of each contact is the one kept, along with the header row.
The download is named contacts (deduplicated).csv.
Choosing what counts as a duplicate
Leave every column unticked to remove only rows that are identical across all columns. That is the safe choice for exports that were accidentally merged twice. Tick one or more key columns when the same person or product can appear with small differences elsewhere, for example the same email with two spellings of a name. By default the comparison ignores capital letters and spaces at the start and end of a cell, which catches most copy and paste duplicates. Tick Case-sensitive if Ann and ann should count as different values.
What the output keeps
Rows keep their original order, so the cleaned list reads the same way as before, just without the repeats. A CSV file comes back as CSV. An Excel workbook comes back as a workbook with every sheet, and only the sheet you chose is cleaned. Values are kept as they were, but formulas are stored as their last results and formatting is not copied. Keep your original file until you have checked the result.
Your files stay on your device
The file is read and compared row by row in a background worker inside your browser. The cleaned copy is created on your device and offered as a download. Your contact lists never touch a server, which keeps you clear of sharing personal data with a third party.
Frequently asked questions
Which copy of a duplicate is kept?
The first one, counting from the top of the sheet. Later copies are removed.
Can I find duplicates by one column only?
Yes. Tick that column, for example Email, and rows count as duplicates when that column matches, even if other columns differ.
Does it ignore upper and lower case?
Yes, by default. Tick Case-sensitive if capitals should make values different.
Will the header row be removed?
No. With First row is a header ticked, the header is always kept and never compared.
Can I see which rows were removed?
Yes. The result lists the removed sheet row numbers, counting the header as row 1.