What does the validator check?

Column-count consistency against the header, quoting/parse errors, duplicate and empty header names, a leading BOM, and mixed line endings.

My file fails an import but validates fine here — why?

The structure is valid; the importer likely objects to the content (types, encodings, required fields). Open the file in OpenCSV to inspect and fix specific cells.

Completely — validation runs in your browser and your file is never uploaded.

/ free tool

CSV Validator & Linter

Validate CSV files free in your browser: inconsistent columns, broken quotes, duplicate headers, BOM and more. No upload.

100% free
Runs in your browser — nothing is uploaded
No signup required

“Import failed on line 4,812” is nobody's favorite error. Run your CSV through this validator first and catch the problems before your database or CRM does.

It checks for rows with the wrong number of columns, unclosed quotes, duplicate or empty header names, UTF-8 BOM issues, and mixed line endings — the classics that break imports everywhere.

Example

Input

name,city
Ada,London,extra

Output

✗ Row 2 has 3 columns (expected 2)

Your data never leaves your device

Like everything at OpenCSV, this tool processes files locally in your browser. There is no upload, no server-side processing, and no copy of your data anywhere — which makes it safe for customer lists, financial exports, and other sensitive files.

/ frequently asked

Frequently Asked Questions

Column-count consistency against the header, quoting/parse errors, duplicate and empty header names, a leading BOM, and mixed line endings.

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