About this tool
JSON and CSV are both extremely common, but they don't map onto each other automatically — JSON supports nested objects and arrays that CSV's flat rows and columns can't represent directly. This tool converts in both directions: paste JSON and get a flattened CSV with nested keys joined by dots (e.g. user.address.city), or paste CSV and get an array of JSON objects with values automatically typed as numbers, booleans, or strings rather than everything staying as text. The conversion direction is auto-detected from your input, so you don't need to manually choose a mode. It's useful for feeding API responses into spreadsheet tools, or turning spreadsheet exports into JSON for use in application code.
Frequently asked questions
How does it handle nested JSON objects when converting to CSV?
Nested keys are flattened into dot-notation column names, so {"user":{"name":"Sam"}} becomes a column called user.name — this keeps the output a valid flat table.
Does it auto-detect which direction to convert?
Yes — paste either JSON or CSV and the tool detects the format and converts to the other automatically.
Are numbers and booleans preserved correctly from CSV?
Yes, values like true, false, and numeric strings are automatically inferred as their proper JSON types rather than being left as plain text.
What happens to JSON arrays when converting to CSV?
Arrays are typically expanded into indexed columns or rows depending on structure, so the tabular output remains usable rather than collapsing into a single unreadable cell.
Can I convert a JSON array of objects directly?
Yes — this is the most common case: an array of similarly-shaped objects converts cleanly into rows with each object's keys becoming columns.