JSON ↔ CSV Converter

Two formats, two audiences

JSON is how APIs and code exchange structured data; CSV is what spreadsheets, BI tools and non-developers open without thinking. Converting between them is a constant chore — exporting an API response for a colleague to review in Excel, or turning a spreadsheet of records into a JSON fixture for tests. This tool does both directions instantly, in your browser.

How nesting is handled

CSV is flat; JSON is not. When you convert JSON → CSV, nested objects are flattened into dotted column names — {"user":{"city":"…"}} becomes a user.city column — and arrays are kept as JSON strings inside a cell. Fields containing your delimiter, quotes or newlines are quoted per RFC 4180 (the rules spreadsheets expect), and columns are the union of keys across all rows so nothing is dropped. Converting CSV → JSON uses the header row as keys and coerces obvious numbers, booleans and null back to real JSON types.

FAQ

My CSV uses semicolons / tabs — will it work?

Yes — pick your delimiter from the dropdown (comma, semicolon, tab or pipe). European locales often export semicolon-separated CSV because the comma is a decimal separator.

Does it handle commas and quotes inside values?

Yes, in both directions. On output, values with delimiters or quotes are wrapped in double quotes with internal quotes doubled; on input, the parser understands the same escaping plus newlines inside quoted fields.

Can I convert a huge file?

Everything runs in your browser, so it's limited by your device's memory rather than a server — comfortable for thousands of rows. For multi-gigabyte pipelines, a streaming tool or a script is the right choice.