CSV Validator
Paste comma-separated data to find unclosed quotes, misplaced quotes, characters after closing quotes, blank records, and rows with different field counts.
A QUICK WALKTHROUGH
How to use this tool
- Paste comma-separated text up to 2 MB.
- Select Check CSV to inspect quoting and compare each non-blank record with the first non-blank record.
- Review the record and line numbers, then correct the source data in your spreadsheet or export.
Common quoting and width checks
The checker accepts comma-separated fields, doubled quotes inside quoted fields, and line breaks inside quoted fields. It reports unclosed quoted fields, quotes inside unquoted fields, characters following a closing quote, blank records, and non-blank records whose field count differs from the first non-blank record.
Useful locations, no automatic edits
Each finding includes a record number and physical starting line. The tool reports problems without rewriting or removing data, so you can fix the original export deliberately.
Defined scope and local limits
LF, CRLF, and CR line endings are accepted. Input is limited to 2 MB, 50,000 records, and 500 fields per record. This is a practical common-issue check, not complete RFC 4180 certification, a schema check, or validation of application-specific constraints. Data stays in your browser.
GOOD TO KNOW
Common questions
Does a clean result prove my CSV follows every CSV standard?
No. It checks common quoting mistakes and consistent record width. CSV dialects and importing applications can apply additional rules.
Can a quoted field contain a comma or line break?
Yes. A correctly quoted field may contain commas and physical line breaks. A quote character inside a quoted field must be doubled.
Does it fix the file?
No. It reports findings with record and line numbers and leaves the input unchanged.
Is my CSV uploaded?
No. Parsing and checks run locally in your browser.