CSV values become JSON strings. JSON numbers are written to CSV exactly as typed (0.50, 1e3), and long IDs are never rounded.
JSON ↔ CSVConvert JSON and CSV
Convert JSON and CSV
without changing values.
Turn a JSON array into a CSV table, or a CSV into JSON. Values are never guessed into numbers or dates, and whatever CSV cannot express (null vs missing vs empty) is reported every time.
No uploadNo number or date guessingLosses are shown
Fictional orders and customers.
Nested objects become "a.b" columns or stay as JSON text. Arrays stay JSON text, are joined with a separator, or get one column per item.
Cells starting with = + - or @ are counted and reported, and can be prefixed with ' so that Excel does not run them as formulas.
How to use it
- Choose a direction: JSON → CSV, CSV → JSON, or format JSON.
- Paste JSON or CSV, or open a file, and press “Convert”.
- Check the options for nesting, empty values and delimiters, and the warnings.
- Copy the result or save it as a file.
FAQ
Are numbers and dates converted automatically?
No. CSV values such as "007", "2026-01-02" or "true" stay strings in JSON. JSON numbers are written to CSV exactly as typed.
How are null and empty strings told apart?
CSV has no way to distinguish null, a missing key and an empty string. When they all become empty cells, a warning says so. You can also write null as the text "null".
Where are JSON syntax errors shown?
The line and column of the error are shown with that line and a marker under the position, which catches trailing commas, single quotes and other invalid JSON.
What is formula injection?
Cells starting with = and similar characters may run as formulas when opened in Excel. The tool counts such cells and can prefix them with ' (off by default because it changes the values).