Clean CSV
Choose how to remove duplicate records or empty rows.
- 1Add input
- 2Adjust settings
- 3Get your result
Tool input and files are processed in this browser without being uploaded.
Before you start
Deduplicate CSV rows using all columns or selected comparison keys, keeping the first match. Empty-row removal is optional; the original column order is retained.
How to use this tool
- Paste content into “CSV input” or choose a local file.
- Choose the delimiter, review the parsed columns, and untick any columns that should not define a duplicate before selecting “Clean CSV”.
- Review the CSV result, then use the available copy or download controls.
Supported inputs and limits
CSV files are limited to 10 MiB and 200,000 cells; pasted input is limited to 1 MiB. Keys are compared exactly, including case and spaces. Formula-like output cells gain an apostrophe by default; spreadsheet apps may remove it after resaving.
Worked example
Example input
id,value 1,a 1,b 2,c
Example options
{
"keys": "id"
}Example output
id,value 1,a 2,c
When something does not work
Correct the reported syntax or range and run again. Formatting is not execution: scripts, SQL, expressions and pasted markup do not run against your system or a remote service.
Frequently asked questions
Are my files uploaded?
No. Files and tool input are processed in your browser. Moving around the site can keep a temporary workspace in the same tab. Refreshing or closing the tab clears it, so download results you want to keep.
What should I check in this result?
Choose the columns that define a duplicate. The first matching row is kept; removing wholly blank rows is optional. Review spreadsheet safety if values begin with formula characters.