CSV Validator
Paste a CSV or open a file and get a list of everything that could stop it importing, with the line number of each fault.
Drag a file here or choose one
Worked examples
A short row and an open quote
id,name,note 1,Ann,ok 2,Bob 3,Cara,"unfinished 4,Dev,ok
Problem, line 3: this row has 2 values but the first row has 3. Problem, line 4: a quoted value that starts on this line is never closed.
Line numbers count from 1. The unclosed quote swallows the rest of the file.
About CSV Validator
When a CSV import fails with a vague error, the cause is usually one of a handful of faults. This validator reads your file by the rules for CSV files and lists every problem it finds with the line number: a row with more or fewer values than the header, a quoted value that is never closed, a quotation mark in the middle of an unquoted value, text after a closing quote, blank lines, empty or repeated column names, characters that were not decoded properly and mixed line endings.
Findings are grouped by how serious they are. Problems stop a clean read. Warnings, such as blank lines or repeated column names, are likely to cause trouble. Notes, such as spaces at the ends of values, are worth knowing. A value that runs over several lines is reported at the line where it starts. If the file has one column but another separator would give several, the validator points that out, because the wrong separator is the most common cause of all.
How to use CSV Validator
- Paste your file or open it. The separator is found, or you can choose it.
- Read the summary: whether the file reads cleanly, how many data rows and columns it has.
- Go through the list of problems and warnings, each with its line number.
- Fix the first problem and check again, since one fault can cause many later ones.
Common uses
- Finding why an import rejects a file
- Checking a file before you send it to a customer or a system
- Spotting unclosed quotes in an export
- Finding rows with a stray comma
Frequently asked questions
What counts as valid?
Every row has the same number of values as the first row, every quoted value is closed, quotation marks inside values are doubled, and the file decodes as text. Blank lines and repeated names are reported as warnings.
Why is one unclosed quote reported as many errors?
Everything after the missing closing quote is read as part of one value. Fix it and check again; the other errors usually vanish.
What is a byte order mark?
Three invisible bytes at the start of some UTF-8 files. Spreadsheet programs use it to recognise UTF-8, but other programs show it as odd characters in the first column name.
What do the odd characters mean?
A diamond with a question mark means a character could not be decoded, usually because the file was saved in a different character set. Text like é means a UTF-8 file was read as older text.
Does the tool change my file?
No. It only reports. Use the CSV cleaner or the delimiter converter to fix and save a corrected copy.