Find CSV problems and clean them safely
Check for shifted columns, blank rows, duplicates, and other CSV problems. Review what was found, then create a new CSV with only the fixes you select.
CSV processing stays in your browser
Your files are not uploaded to a server.
Your original CSV stays unchanged. Rows that cannot be judged safely are never rewritten automatically. The file is processed in your browser and is not sent externally.
Choose a CSV
Choose a CSV with column names in the first row. It is not sent anywhere.
Drag and drop a CSV here
1 CSV, up to 50MiB (some devices may not finish files with many rows, columns, or long cells even below 50MiB)
If the file looks wrong
Change these only if the text or columns look wrong.
What this tool checks and its limits
- Only completely blank rows and rows whose extra cells after the first row are all empty are selected by default.
- Rows with a different column count, spaces in extra cells, or identical content stay unselected until you review them.
- Column counts are compared with the column names in the first row.
- Duplicates require every cell and the column count to match exactly.
- Commas and newlines inside quotes are supported. An unclosed quote stops processing without repair.
- UTF-8, Shift_JIS, CP949, Big5, GB18030, Windows-1252, and ISO-8859-1 are supported.
- One file up to 50MiB can be processed.
- The original file stays unchanged and a separate CSV is created.
- CSV data and file names are not sent to an external server.
- This check does not confirm whether values are correct or follow the rules of the program that will import them.