Free CSV to JSON & JSON to CSV Converter Tool Online
Transform CSV files into JSON or convert JSON arrays back to CSV with automatic type detection. Fast, browser-based, and privacy-friendly.
IN: CSV or JSON · OUT: JSON or CSV · RUNS: 100% in your browser
[
{
"name": "Ada Lovelace",
"role": "Engineer",
"active": true
},
{
"name": "Grace Hopper",
"role": "Admiral",
"active": true
}
]Frequently asked questions
Does the converter detect column types automatically?+
Yes, when converting CSV to JSON, numeric and boolean-looking values (like 42 or true) are automatically converted to their proper JSON types rather than staying as strings, using dynamic typing.
What if my CSV doesn't have a header row?+
This tool expects the first row to be column headers, which become the JSON object keys. If your CSV has no header row, add one manually before converting, or the first data row will be treated as headers.
Can I convert a single JSON object, not just an array?+
Yes, if you paste a single JSON object instead of an array, the tool automatically wraps it in an array of one before generating a single-row CSV.
How are commas inside CSV values handled?+
Values containing commas, quotes, or newlines are automatically quoted according to the CSV specification (RFC 4180), so they round-trip correctly through the parser.
What happens if my CSV rows have different numbers of columns?+
Rows with fewer values than the header will have missing fields when converted to JSON; extremely inconsistent CSVs may produce a parse error, which will be shown as the output instead of JSON.
Is my data uploaded to a server during conversion?+
No, both directions run entirely in your browser using a JavaScript CSV parsing library — your data never leaves your device.