CSV Validator

How to use the csv validator

1. Paste CSV text or choose a CSV file. A sample with problems is loaded so you can see the report.
2. Choose the separator if it is not a comma, and say whether the first row is a header.
3. Read the summary, then the table of problems with the line, record, field and character of each.
4. Fix the first problem, because later ones are often caused by it, and copy the report if you need it.

What counts as a problem

The checks follow RFC 4180, the common description of CSV. A value that contains the separator, a quote or a line break must be inside double quotes, and a quote inside a quoted value is written twice. A quote in the middle of an unquoted value is an error, text right after a closing quote is an error, and a quote that is never closed makes the rest of the file one value. Every record should hold the same number of values as the first record, and a record with more or fewer is an error with its line number.

Some findings are warnings because many programs accept them: a blank line in the middle of the data, a header that is blank or repeated, line endings that are LF or mixed instead of CRLF (checked only for a file you choose, since a text box hides them), and a byte order mark at the start. The summary also shows the number of records and columns that were read.

Reading the report

Line is the physical line in the text where the problem is. Record is the row number in the data, counting the header as 1, which differs from the line when a quoted value spans lines. Field is the position of the value in the row, and Character is the position within the line, shown when the problem is at a specific character.

Only the first 100 problems are listed, with the total shown above. A single broken quote often changes how everything after it is read, so fix the first error and check again. This tool checks structure only. It does not decide whether values make sense. To convert a clean file, use the CSV to JSON converter or the CSV to SQL tool, and for list cleanup the text line tools. Files up to 5,000,000 characters are checked in your browser and never uploaded.

Assumptions and limits

• CSV rules are those of RFC 4180, with the separator you choose.
• Line, record, field and character numbers start at 1.
• Only the first 100 problems are listed, though the total is counted.
• Blank lines, repeated headers and line ending style are reported as warnings, not errors.

Formulas reviewed October 10, 2026. See the calculation methodology for how SumPanda rounds, tests and sources its formulas.

Frequently asked questions