— tool guide

CSV Validator

Validate a CSV file against configurable rules. Check column count, required fields, data types, allowed values, date formats, and uniqueness. Get a detailed error report per row.

Open CSV Validator → free, no sign-in

— try it live open full screen ↗

— what it is

Before importing a CSV into a database or processing it with a script, you need to know it is well-formed and contains valid data. This tool lets you define a schema — column names, data types, required status, allowed values, date formats, and uniqueness constraints — and validates every row against it, producing a clear error report showing exactly which rows and columns fail and why.

— what it does

✓Column presence and count validation
✓Per-column rules: required, data type (text, integer, float, boolean, date, email, URL)
✓Allowed values list (enum validation)
✓Date format validation with configurable format string
✓Uniqueness constraint per column
✓Min/max value and length constraints
✓Detailed error report: row number, column, rule, and actual value
✓Summary: pass/fail counts and error percentage
✓Download the error report as CSV

— who it's for

→Developers validating CSV imports before writing to a database
→Data engineers enforcing schema on supplier data feeds
→Analysts checking data quality before running a pipeline
→Teams reviewing user-submitted CSV exports for compliance

— how to use it

01 Open the CSV Validator

02 Upload your CSV file

03 Add a validation rule for each column you want to check

04 Click Validate

05 Review the error report — click any error row to highlight it in the preview

06 Download the error report as a separate CSV for sharing

— at a glance

Category	Data Tools
Cost	Free
Sign-in required	No
Files uploaded	Never — runs in your browser
Published	May 11, 2026

— frequently asked questions

Can I save my validation schema?

The schema is held in session for the current visit. Copy the schema JSON from the export option to reuse it later.

Does it validate emails properly?

It checks that values match the pattern user@domain.tld — a format check, not a delivery check.

What date formats are supported?

Any format string using YYYY, MM, DD, HH, mm, ss tokens — for example YYYY-MM-DD or DD/MM/YYYY.

Can it handle large files?

The tool processes files in your browser. Files up to a few thousand rows are fast; very large files may take a moment.

Is this free?

Yes — free with no sign-in.

— ready to use it?

Free, instant, no sign-in required. Opens directly in your browser.

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