Check a CSV before importing it.

Find missing values, repeated rows and inconsistent column counts. Useful for checking a spreadsheet export before moving it into another system.

Everything stays in this browser. No upload, account or AI. This checks structure, not whether the information itself is correct.

Paste CSV with a header row

The example includes a duplicate row and a missing reference. Select Check CSV to see them.

Accepts comma-separated values, quoted fields and line breaks inside quotes. Blank lines are ignored. Nothing is changed or removed.