CSV Analyzer
Drop a file and find out what is actually in it before you load it anywhere: what each column really holds, how much is missing, which rows are malformed, and whether there are duplicates.
Output appears here as you type.
Runs entirely in your browser. Nothing you paste here is uploaded or stored.
Questions
Is my file uploaded anywhere?
No. Parsing happens in your browser as a pure function, and the page is served with a Content-Security-Policy of connect-src ‘none’, so the browser refuses to let it open a network connection at all. That is what makes it safe to drop a real export — the kind with customer names and email addresses in it.
My file has commas inside quoted fields. Will it break?
No. The parser handles quoted delimiters, newlines inside quoted fields, doubled quotes, a UTF-8 BOM, semicolon and tab delimiters, and lone-CR line endings from old Mac exports. It also reports rows whose field count does not match the header instead of quietly dropping them.
What counts as a missing value?
An empty cell, plus the tokens listed in the options — NULL, N/A and similar by default. Exports differ on how they mark absence, so the list is editable rather than assumed.
What are ragged rows?
Rows whose field count does not match the header, usually an unescaped delimiter inside a value or a broken export. They are reported with line numbers rather than silently padded, because that is normally the bug you came here to find.