JSON to CSV Converter
Paste an array of JSON objects on the left, get a CSV spreadsheet on the right. Headers are derived from the union of keys; nested values are JSON-encoded into cells.
How to use this tool
Paste a JSON array of objects into the input box. A single object also works (it becomes a one-row CSV).
CSV output appears instantly on the right. The first row is the header (all unique keys, in first-seen order).
Use the Copy button and paste into Excel, Google Sheets, Numbers, or any CSV consumer.
Cells containing commas, quotes, or newlines are automatically quoted per RFC 4180. Nested objects and arrays inside a cell are serialized as compact JSON so you do not lose data.
Everything runs locally — useful for converting private API exports into spreadsheets without exposing the data.
Frequently asked questions
How are nested objects and arrays handled?
They are JSON-encoded into the cell. For example, {"address": {"city": "NYC"}} produces a cell containing {"city":"NYC"}. This preserves the data while keeping the CSV flat. For fully expanded columns, flatten the JSON upstream.
What if my objects have different keys?
The converter takes the union of all keys across every object and uses that as the header row. Missing values become empty cells.
Does it support semicolon-separated CSV (European format)?
The default output is comma-separated per RFC 4180. You can post-process for other delimiters, or paste into a spreadsheet app that lets you choose the delimiter on import.
Is the data uploaded?
No. Conversion is fully client-side. Even sensitive exports never leave your browser.