CSV Field Validator
Apply named validation rules to CSV columns and download a row-by-row error report.
How do I assign different checks to CSV columns?
Provide a JSON object mapping column names to rules such as email, url, uuid, integer, or iso-date. The report lists the row, column, submitted value, and failed rule.
Your result
A little clarity, right here.
Start with your own content or load the example. Your result will appear here.
Three simple steps
How to use CSV Field Validator
Choose your input and adjust the options.
Review the preview and run the tool.
Download the result and keep your original.
Common questions
Good to know
Understand the result.
Keep the original.
Is this tool free, and are my files uploaded?
This tool is free with no account required. The work happens in your browser. Your input and files are not sent to a processing server.
What are the limits and details?
Up to 10,000 rows and 50 rule assignments. Row numbers include the header row. The tool reports validation errors without silently changing your source values.
Limits: 500,000 characters per text field; files up to 20 MB each, 10 files and 50 MB total. Processing stops after 30 seconds.