Spreadsheet validator
Validate CSV & Excel Files Online
Validate a CSV file before you import it, email it, or hand it to a client. SheetSweep checks spreadsheet structure and points to duplicate rows, missing cells, header problems, mixed date formats, and formula risk.
The Excel validator is read-only: it diagnoses the file without rewriting any values. Findings include exact rows and cells so you can decide what needs attention instead of trusting a vague pass-or-fail result.
Check CSV, TSV, XLSX, or XLS files and download a shareable HTML report. The spreadsheet itself remains untouched.
Open the ValidatorPrivate by design. Your files never leave this browser tab — no uploads, no servers, no signup. What happens in your spreadsheet stays in your spreadsheet.
1Choose one fileAdd a CSV, TSV, XLSX, or XLS file and select a worksheet if needed.
2Read the diagnosisReview problems, warnings, and informational findings tied to exact cells.
3Download the reportTake a clear validation report with you while the source file stays unchanged.