CSV cleaner

Drop a CSV file, choose what to tidy up and download the clean version. You see how many rows were removed and a preview of the result. Nothing is uploaded.

  • Free
  • No sign-up
  • Runs in your browser
clean-csv

100% private — your file is read in your browser and never uploaded.

Next step

Keep going with your result in another tool. Nothing is uploaded.

How it works

Open the file

Drop it on the box or paste the data.

Choose the cleaning

Spaces, empty rows, duplicates, empty columns and the separator.

Download

You get the tidy CSV, and a report of what changed.

Tidy a messy CSV in a few clicks

Data exported from a shop, a form, a CRM or a spreadsheet is rarely ready to use. There are blank rows at the bottom, the same customer appears three times, names have stray spaces in front and behind, a column nobody filled in takes up room, and the separator is not the one your next program expects. These small flaws break imports and distort counts. This tool cleans them in one pass.

What it can fix

  • Spaces around cells. " Anna " and "Anna" are different values to a computer, so matching and sorting go wrong. Trimming removes the extra spaces at both ends, and you can also collapse repeated spaces inside a cell.
  • Empty rows. Rows where every cell is blank are removed.
  • Duplicate rows. Rows that are identical to an earlier one are dropped, keeping the first.
  • Empty columns. Columns with nothing in any row are removed.
  • The separator. Convert a semicolon file to commas or the other way round, or to tabs, so it opens correctly in the program that will receive it.
  • Quotes. Optionally put every cell in quotes, which some importers require.

See what changed

Before downloading you see a preview of the first rows and a count of everything that was done: rows read and kept, empty rows and duplicates removed, columns dropped and cells trimmed. That way there are no surprises.

Encoding and Excel

The file is read as UTF-8, with Windows-1252 as a fallback, and the result is saved as UTF-8 with a marker that makes Excel show accents correctly. Quoted cells with separators or line breaks inside are handled properly.

Limits

Rows are compared as a whole, so two rows that differ in a single cell are both kept. The tool does not fix wrong values, merge similar names or validate emails. Files up to 60 MB are accepted, and everything happens in your browser. To look at the data first, use the CSV viewer.

Frequently asked questions

How do I remove duplicate rows from a CSV?
Open the file, tick Remove duplicate rows and download the result. The first copy of each row is kept.
How do I change a CSV from semicolons to commas?
Choose Comma in the separator of the result. The file is saved with commas, quoting cells when needed.
Will it change my data?
Only what you select. Trimming spaces changes the cells that had extra spaces, and the report tells you how many.
Are rows with only spaces treated as empty?
Yes if you also trim the cells: spaces are removed first, so the row becomes empty and is deleted.
Does it keep the header?
Yes. If the first row is the header, it is kept and is never treated as a duplicate.
Is my file uploaded?
No. The cleaning is done in your browser.

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