About CSV to JSON & JSON to CSV Converter
Convert CSV to JSON and JSON to CSV — both directions in one tool. Paste your data, pick the delimiter, and get clean, ready-to-use output. Flip the direction to convert the other way; everything runs in your browser.
How to Use
- Choose the direction: CSV → JSON or JSON → CSV.
- Paste your data and set the delimiter (comma, semicolon, tab, or pipe).
- For CSV → JSON, choose whether the first row is a header.
- Copy the converted output.
Why Use This Tool?
- Accurate — built on precise, well-tested mathematical formulas.
- Instant — all calculations happen client-side for zero latency.
- Private — no data is sent to any server; your information stays on your device.
- Free — no sign-up, no limits, no hidden costs.
Frequently Asked Questions
Does the first row become the JSON keys?
In CSV → JSON, if you enable the header option the first row is used as the property names for each object. In JSON → CSV, the object keys become the header row automatically.
How does it convert JSON to CSV?
Paste an array of objects and it builds a CSV: the union of all keys becomes the header row, and each object becomes a row. Values containing the delimiter, quotes, or line breaks are safely quoted per CSV rules.
Can it handle commas or nested data inside a value?
Yes. Quoted CSV fields may contain the delimiter (e.g. "Smith, John"), and when going JSON → CSV, nested objects/arrays are serialized into the cell so nothing is lost.
Is my data uploaded anywhere?
No. Both conversions run entirely in your browser, so even sensitive spreadsheets or API payloads never leave your device.