CSV validator and checker
Find out what’s wrong with a CSV before an import fails: broken quotes, ragged rows, duplicate headers, blank lines, stray spaces and formula-like cells.
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- Instant results
- No account needed
Drop a CSV file hereUp to 10 MB · processed in this tab, never uploaded
Your result appears here as soon as you add a file.
How it works
Three steps, nothing to install- 01
Drop in the CSV you’re about to import.
- 02
Read the report: errors first, then warnings, with the rows they affect.
- 03
Fix the problems with the other tools, or in the workspace, and check again.
Good to know
What the tool does, exactlyWhat it checks
Unterminated quotes, rows with more or fewer fields than the header, blank or repeated column names, empty rows, exact duplicate rows, leading and trailing spaces, cells that start like spreadsheet formulas, mixed line endings and files that aren’t valid UTF-8.
Column profile
Each column gets an inferred type (number, boolean, ISO date or text), a count of blank cells and the number of distinct values, so you can spot a column that should be numeric but isn’t.
Private by design
The file is processed in your browser and never uploaded, so it’s safe for customer lists and financial exports.
Questions
About csv validatorHow are rows numbered?
Like a spreadsheet: the first line of the file is row 1, so with a header row the first record is row 2.
Does it detect the delimiter?
Yes. Comma, semicolon, tab and pipe are detected automatically, and you can override the guess.
Why is a formula-like cell a problem?
Cells that start with =, +, - or @ can run as formulas when the file is opened in a spreadsheet, which is a known security risk called CSV injection. Neutralise them with the formula sanitizer.
Keep going
All free toolsCleaning the same
files every week?
The free workspace saves each dataset, with undo and a full history. See features