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  3. CSV Data Validator
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CSV Data Validator

Validate CSV data against custom rules

Define validation rules for each column, required fields, allowed values, numeric ranges, regex patterns, unique constraints, and the tool checks every row against them. You get a detailed error report showing exactly which cells fail and why, making it easy to fix issues before data goes into production.

Runs in your browser and files never uploadedMore csv & data analysisJump to full guide

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CSV Data Validator: a worked example

Before an import you must guarantee every email is well-formed and every age is a positive integer.

Rules

email: regex · age: integer 0–120 · country: in [US,DE,FR]
CSV Data Validator produces

Report

17 rows failed: 11 bad email, 4 age out of range, 2 unknown country
Failing rows listed with line numbers

You declare per-column rules and get back exactly which rows and cells violate them, with line numbers, turning a vague "the import keeps failing" into a precise fix list. Validating before load is far cheaper than rolling back a bad import.

What is CSV Data Validator?

Define validation rules for each column, required fields, allowed values, numeric ranges, regex patterns, unique constraints, and the tool checks every row against them. You get a detailed error report showing exactly which cells fail and why, making it easy to fix issues before data goes into production.

How to use

  1. 1Upload your CSV
  2. 2Define validation rules per column using the rule builder
  3. 3Run the validation
  4. 4Review the error report grouped by column and rule type
  5. 5Export passing rows, failing rows, or the error report

Key features

  • Rule types: required, type, range, enum, regex, unique, cross-column
  • Error vs. warning severity levels
  • Grouped error report with cell-level detail
  • Save and reuse validation profiles
  • Export passing rows separately from failing rows
  • Batch validation across multiple files with the same profile
  • Summary statistics: pass rate, top failing rules, worst columns

Common use cases

  • Incoming data quality gates

    Validate vendor or partner data deliveries against agreed-upon rules before accepting them.

  • Pre-import checks

    Catch constraint violations (nulls in required columns, out-of-range values) before loading into a database.

  • Regulatory compliance

    Ensure datasets meet format and completeness requirements mandated by regulatory standards.

  • Form submission review

    Validate bulk form responses exported as CSV to catch invalid emails, phone numbers, or missing fields.

  • Continuous quality monitoring

    Reuse saved validation profiles to check recurring data feeds on a regular schedule.

Rule-Based CSV Validation

Data validation is the gatekeeping step between raw CSV data and trusted datasets. This tool lets you build a validation profile per column without writing code. Supported rule types include: required (no blanks), data type (must be integer, date, email, etc.), range (min/max for numbers or dates), allowed values (enumerated list), pattern (regex match), uniqueness (no duplicates), and cross-column rules (column A must be less than column B).

The error report groups failures by rule type and severity (error vs. warning), and you can download it as a CSV for integration into automated quality pipelines.

Frequently asked questions

Can I save validation rules for reuse?

Yes. Save your rule set as a validation profile and load it the next time you receive a file with the same structure.

What is the difference between errors and warnings?

Errors indicate hard failures (data that must be fixed). Warnings flag potential issues worth reviewing but that may be acceptable.

Can I validate across columns?

Yes. Cross-column rules let you enforce relationships like "end_date must be after start_date" or "total must equal quantity times price."

Does it handle large files?

Yes. Validation runs in your browser and handles files with hundreds of thousands of rows.

Private by design

Rows and columns are parsed and transformed in memory in your browser. No record ever reaches a server.