CSV to JSON / JSON to CSV Converter
Convert spreadsheet-style CSV to JSON or back again, with delimiter detection and header control.
Move tabular data between CSV and JSON in either direction. Turn a spreadsheet export into an array of JSON objects for an API or a script, or flatten JSON records back into CSV for a spreadsheet. You can paste text directly or drop in a file, and the converter handles the fiddly bits — choosing the delimiter, treating the first row as headers, and flattening nested fields. It all runs in your browser.
Delimiters and headers
Real-world CSV isn't always comma-separated: European exports often use semicolons, and some files are tab- or pipe-delimited. Leave the delimiter on auto-detect and the tool works it out, or pick one explicitly. The header option decides whether the first row supplies the object keys (so name,age becomes {"name": …, "age": …}) or whether every row is treated as plain data. Getting these two settings right is usually all it takes for a clean conversion.
Going from JSON back to CSV
Converting JSON to CSV raises a question CSV can't answer on its own: what to do with nested objects, since a spreadsheet cell is flat. The flatten option unpacks nested structures into dotted column names so nothing is lost, and value parsing can infer numbers and booleans rather than leaving everything as quoted strings. When the result looks right, copy it or download it straight to a file.
Frequently Asked Questions
Can I convert in both directions?
Yes. CSV becomes an array of JSON objects, and JSON records become CSV rows. The swap button lets you flip direction without re-pasting your data.
What if my file uses semicolons or tabs instead of commas?
Choose the matching delimiter, or leave it on auto-detect and the tool will identify comma, semicolon, tab or pipe separators for you.
How are nested JSON objects handled when converting to CSV?
Turn on flatten to unpack nested objects into dotted column names (like address.city), so nested data maps cleanly onto flat CSV columns instead of being dropped.
Can I upload a file instead of pasting?
Yes. Drop a file onto the drop zone or select it, and you can download the converted result as a file too. Everything is processed locally in your browser.