DATA · FREE TOOL
CSV duplicate checker
Find duplicate and blank IDs before they become a bigger problem.
This can change affected exported values. Import numeric-looking IDs as text in spreadsheet apps to keep leading zeros.
Your result is ready.
Download CSV ↓Scroll sideways to see every column. You can also focus the table and use the arrow keys.
What does the checker look for?
IDs are compared as exact text. Case, whitespace and leading zeros matter; “001” and “1” are different IDs. Empty or whitespace-only keys are reported separately. Record numbers start at one after the header; quoted fields may span multiple physical lines.
The report includes every affected original record and three added columns describing the issue. Header names are trimmed, and missing trailing cells become empty text. The original file stays unchanged.
Empty physical lines are skipped; explicitly empty CSV records are retained. Record numbers refer to data records after skipped lines.