CSV Validator

CSV Validator

Updated August 20, 2026

CSV validator online. Check CSV files for errors, broken quotes, and missing columns. Validate CSV free.

Features

  • Report unclosed quotes with a line number
  • Warn on empty headers, duplicate headers, empty rows, and ragged widths
  • Show delimiter and shape stats
  • Does not upload the file
  • Works on TSV and semicolon CSV too

Common Use Cases

  • Gate a CSV before a database import
  • Explain why a parser stopped at row 4,081
  • Catch duplicate column names before JSON conversion
  • Check an Excel export for blank lines at the end
  • Validate a partner file against basic hygiene, not a full schema

What “valid CSV” means here

There is no single CSV spec in the wild, but RFC 4180 plus “every row has the header width” covers most importer failures. We do not type-check cells or enforce required columns. That is schema work for your pipeline.

Examples

Valid - Clean
id,name
1,Ada
Valid - Duplicate header
id,id
1,2
Invalid - Unclosed quote
id,name
1,"Ada

Frequently Asked Questions

Is a ragged row an error?

We treat it as a warning and pad or trim so the table still builds. Some importers will reject it instead.

Do you fetch a schema URL?

No.

Related Tools

CSV Viewer

See the rows

Try it

CSV Diff

Compare two files

Try it

Tips

  • Fix quotes first. Everything else is guesswork if a quote is left open.
  • Empty last line is normal. Completely empty extra rows are usually an Excel artifact.