CSV to JSON Converter
Convert between CSV and JSON in both directions: map the first CSV row to keys of a JSON array of objects, or turn an array of objects back into CSV. Delimiter auto-detection, nested-object flattening and JSON stringify are supported — all done locally in your browser.
How to use
- Pick the direction at the top: CSV → JSON or JSON → CSV; the input label and hint update accordingly.
- Paste your content and choose the delimiter (usually "Auto-detect" recognizes commas, semicolons or tabs).
- For CSV → JSON, the first row is treated as field names and every other row becomes one object; for JSON → CSV, the input should be an array of objects and the header is derived from all keys.
- With nested objects choose "Flatten as dot path" or "Stringify as JSON"; arrays and other non-flattenable values are written as JSON strings with a notice.
- Click "Convert" to see the result, then use "Copy" or "Download file"; "Example" loads demo data instantly.
FAQ
Are CSV numbers converted to JSON numbers?
No type inference is performed: every cell is output as a string so conversions round-trip losslessly. If your JSON side does have numeric fields, their text form is kept as-is when exporting to CSV.
How are quoted fields or fields containing delimiters handled?
The parser follows common CSV rules: fields may be wrapped in double quotes, inner quotes are escaped by doubling them, and delimiters or newlines may appear inside quotes. Exporting applies the same quoting automatically.
How are nested objects and arrays in JSON converted to CSV?
In flatten mode, nested objects become dot-path keys such as user.name; arrays cannot be expressed as columns, so they are written as JSON strings with a notice. In stringify mode, all objects and arrays are written as JSON text.
Is my data uploaded to a server?
No. Parsing and generation happen entirely in your browser — the content you paste never leaves your device.