CSV Validator
Free CSV validator that checks for malformed rows, duplicate headers, delimiter issues, and encoding problems. Runs entirely in your browser - no uploads required.
CSV Input
Validation Report
- No issues found.
Frequently Asked Questions
What CSV errors does this validator detect?
Our validator detects malformed rows, duplicate headers, inconsistent column counts, empty headers, BOM (Byte Order Mark) issues, and delimiter problems. It also provides detailed error reporting with row numbers.
Is my CSV data secure when using this validator?
Yes, absolutely. The validation runs entirely in your browser using client-side JavaScript. No data is uploaded to any server - everything stays on your device for maximum privacy and security.
What file formats are supported?
We support standard CSV files with comma, semicolon, tab, or pipe delimiters. The tool automatically detects the delimiter and handles various line endings (Windows, Mac, Unix).
Can I validate large CSV files?
Yes, within browser memory limits. For very large files (100MB+), we recommend splitting them into smaller chunks using our CSV splitter tool first.
How do I fix CSV validation errors?
The validator provides specific error messages with row numbers. Common fixes include: removing duplicate headers, ensuring consistent column counts, fixing delimiter issues, and removing BOM characters.
Does this work with Excel-generated CSV files?
Yes, it works with CSV files exported from Excel, Google Sheets, and other spreadsheet applications. It handles Excel's specific formatting quirks like BOM and various delimiters.
Quick Links
What is CSV Validation?
CSV validation is the process of checking CSV (Comma-Separated Values) files for structural integrity, data consistency, and formatting issues. A well-formed CSV file should have consistent column counts, unique headers, proper delimiter usage, and clean data formatting. For comprehensive data processing, explore our complete collection of CSV tools.
Common CSV Errors and How to Fix Them
1. Inconsistent Column Counts
Problem: Some rows have more or fewer columns than the header row.
Fix: Ensure all data rows have the same number of columns as the header. Add empty cells or remove extra columns as needed.
2. Duplicate Headers
Problem: Multiple columns have the same header name.
Fix: Make each header unique by adding numbers or descriptive suffixes (e.g., "Name_1", "Name_2").
3. Empty Headers
Problem: Some header cells are empty or contain only whitespace.
Fix: Provide meaningful names for all columns or remove empty columns entirely.
4. BOM (Byte Order Mark) Issues
Problem: Invisible BOM characters at the beginning of the file cause the first column to appear with extra characters.
Fix: Save the file as UTF-8 without BOM or use our validator to detect and handle BOM issues.
Validation Results Explained
| Status | Meaning | Action Required |
|---|---|---|
| ✓ Valid | CSV file is properly formatted | No action needed |
| ⚠ Warnings | Minor issues that may cause problems | Review and fix if needed |
| ✗ Errors | Critical issues that will cause problems | Must be fixed before processing |
💡 Pro Tips for CSV Validation
- • Always validate CSV files before importing into databases or applications
- • Use consistent delimiters throughout your file (comma, semicolon, or tab)
- • Quote fields that contain special characters or the delimiter itself
- • Remove BOM characters when saving files to avoid header issues
- • Test with a small sample before processing large datasets
- • Use our CSV to JSON converter for data transformation
- • Explore our comprehensive CSV validation guide for detailed instructions