CSV ↔ JSON converter
Convert CSV to JSON or JSON to CSV locally. Choose delimiters, headers and empty-cell handling, then copy or download the result. Free and ad-free.
Enable JavaScript to use this interactive tool. Paste input, choose options, then copy or download the result, or save it to your notebook.
Details and limits
CSV cells stay strings (or null for empty cells). Choose headers and delimiter explicitly. Missing cells use the empty-cell setting; extra cells and duplicate headers are errors. Nested JSON can be rejected or serialized into a cell. Output is limited to 100,000 cells.
Example and common questions
Convert CSV rows to JSON records
- Direction
- csv to json
- Delimiter
- comma
- Header row
- yes
- Empty or missing cells
- empty string
- Nested JSON values
- reject
name,ready
Maya,true[
{
"name": "Maya",
"ready": "true"
}
]Why are numbers and booleans strings?
CSV cells remain strings. The text true becomes "true", and a number stays text. Empty or missing cells follow the selected empty-string or null setting.
How do headers and delimiters work?
Choose the delimiter and whether the first row contains headers explicitly. With headers, rows become objects; without headers, rows become arrays of cells.
Can nested JSON become CSV?
Yes, with Nested JSON values set to json. Nested objects and arrays are then serialized into a cell. The reject setting reports an error instead.
Common errors and limitations
Look for duplicate headers, extra cells, unterminated quotes or characters after a closing quote. When converting JSON, use an array and choose JSON-in-cell handling if its values are nested.