✓ CSV Validator
Check CSV files for column consistency, unterminated quoted fields, and malformed records. Reports row numbers and column counts — all in your browser, no upload.
About the CSV Validator
This CSV validator runs entirely in your browser. Paste your CSV, choose the delimiter, and click Validate to scan it for common structural problems. The validator parses each row according to RFC 4180 rules: fields may be quoted with double quotes, quoted fields may contain newlines and the delimiter, and embedded quotes are escaped by doubling (""). It checks for unterminated quoted fields, inconsistent column counts, and reports the expected vs. actual column count for each problem row.
What does it check?
- Unterminated quoted fields — a field that opens with
"must close with"on the same line or a subsequent line. - Column consistency — every data row should have the same number of fields as the header (or the first row).
- Embedded newlines — allowed only inside quoted fields; a newline outside quotes starts a new record.
- BOM detection — a leading byte-order mark is reported so you can remove it.
- Empty rows — blank lines are flagged as they may indicate missing data.
How to use the validator
- Paste your CSV into the input box.
- Select the delimiter (comma, semicolon, tab, or pipe).
- Tick "First row is header" if the first row contains column names.
- Click Validate.
- Read the result panel — valid CSV reports the row and column counts; problems list each issue with its row number.
Frequently asked questions
Does it support quoted fields with newlines? Yes. According to RFC 4180, a field wrapped in double quotes may contain newline characters. The validator handles this correctly.
Why are my columns inconsistent? The most common causes are a missing comma, an extra comma, or an unquoted field that contains the delimiter. Check the reported row number.
Is my CSV uploaded? No. All validation happens locally in your browser.