CSV schema validator
Check CSV columns, data types and value constraints against an explicit data contract.
Use happytails-csv-contract-v1 with text, integer, decimal, boolean or date types. Numeric bounds are decimal strings. Extra columns are rejected unless allowExtraColumns is true. Optional empty cells skip value checks. Up to 1,000,000 characters, 10,000 data records, 100 columns and 100,000 cells across the sources. Files for multi-source tools are limited to 4,000,000 bytes total. Reports retain at most 500 diagnostic findings and state any omitted count. CSV and JSON outputs are limited to 4,000,000 characters. Paste CSV data with unique column headers. Quoted multiline cells are supported. Results update as you type. Up to 1,000,000 characters.
Your result
How to use CSV schema validator
- Paste the CSV to validate.
- Define columns and constraints in the displayed JSON contract.
- Review violations by field and data-record number, then download the report.
Useful next steps
Prepare the source
Paste the CSV to validate.
Choose the matching rules
Define columns and constraints in the displayed JSON contract.
Review and keep the result
Review violations by field and data-record number, then download the report. Use happytails-csv-contract-v1 with text, integer, decimal, boolean or date types. Numeric bounds are decimal strings. Extra columns are rejected unless allowExtraColumns is true. Optional empty cells skip value checks.