Why duplicate headers are dangerous
Many CSV readers convert each row to an object keyed by the header. If two columns are named “email”, one value may replace the other. Other systems reject the entire import, and blank names can shift later fields into the wrong schema.
Safe repair steps
- Compare normalized header names for exact duplicates.
- Replace blank names with stable column labels.
- Suffix repeats deterministically so every field remains addressable.
- Check every row against the repaired header width.
- Keep an audit mapping from original to repaired names.
What CSV Clinic outputs
The browser-only repair creates unique nonblank headers, equal-width rows, Excel-safe UTF-8 output, and a JSON report that documents each change. Your source data remains on the device.