Fix CSV

Make a broken CSV open cleanly.

Detect the delimiter and encoding, see exactly what was parsed, and export UTF-8 CSV that Excel opens without mangled accents, split columns or lost leading zeros.

Drop a CSV file

CSV, TSV or plain text up to 5.00 MB — or paste below.

Choose a file

How it works

  1. 01Open a CSV file or paste the text.
  2. 02FormatOnce guesses the delimiter; override it and the encoding if the preview looks wrong.
  3. 03Check the parsed preview and any warnings.
  4. 04Export UTF-8 CSV with a BOM so Excel reads it correctly.

Limits

  • Files up to 5.00 MB.
  • Encodings: UTF-8 and Windows-1252.
  • Every value is kept as text — no numbers or dates are guessed.

Questions & limits

Why do my accents look like é?
The file is probably Windows-1252, not UTF-8. Switch the input encoding and the preview will fix itself.
Will leading zeros survive?
In the file itself, yes: FormatOnce never converts values to numbers, so 00123 stays 00123 and long IDs keep every digit. Excel is a separate matter — if you double-click the CSV it may still display 00123 as 123. To keep it visible, use Data → From Text/CSV in Excel and set those columns to Text on import, or open the file in a tool that does not guess types.
What is the BOM for?
Excel on Windows assumes the system encoding unless a UTF-8 byte order mark is present. The BOM makes accents open correctly.
Why escape cells starting with =?
Spreadsheets execute them as formulas, which is a known CSV injection risk. Escaping keeps them as text — you can turn it off to keep the literal data.