Clean and diagnose CSV and Excel data online
Import CSV, TSV, JSON, JSONL, XLSX or Parquet. Automatically diagnose missing and malformed values, suspicious numeric outliers, inconsistent categories and mixed types. Review suggested repairs with before/after examples. Match possible duplicate records using exact values, token fingerprints or multi-column evidence with confidence scores. Undo changes and export results. Files are processed locally in your browser.
Belgian business validation
Columns named for Belgian enterprise/VAT numbers, IBAN, structured payment references and postcodes receive appropriate format checks. Invalid values are flagged, never silently changed. A postcode check verifies its format and numeric range, not whether it exists in the official register.
Review duplicates before deleting anything
Exact matching, token fingerprints and multi-field matching with evidence and adjustable score thresholds group possible duplicate records. A matching name is not proof two records belong to the same person or company. Select specific rows for removal, or leave them untouched. Manual removals do not appear in exported recipes.
Repeat cleanups with a JSON recipe
Review consistent category spellings or fill missing fields from rows sharing a valid enterprise number (only when source values agree). Undo or redo cleaning operations and save a versioned recipe without your source data, and reapply it to a future dataset containing the same columns. Download results as CSV or JSON; CSV export neutralizes spreadsheet formulas in text values.
Frequently asked questions
Is an account required?
No. Import, editing and export work without an account. No data-processing requests are sent to a server.
Are there limits?
Files are limited to 12 MB, up to 25,000 rows and 100 columns for responsive local processing. Incomplete imports are rejected rather than silently producing a partial clean file.
Does it use OpenRefine?
The review workflow is inspired by the open-source OpenRefine project; this is an independent browser implementation using existing GratisTools parsers. It is not an OpenRefine embed.
Frequently asked questions
Is this tool free?
Yes. The core tool is free to use in your browser.