CSV to JSON & JSON to CSV Converter
Convert between CSV and JSON instantly - all processing happens in your browser, nothing is uploaded.
CSV Input
JSON Input
Quick Tips
- All conversion happens locally in your browser - nothing is uploaded.
- Wrap CSV fields containing commas or quotes in double quotes.
- JSON to CSV expects an array of objects, e.g.
[{...}, {...}]. - Use the delimiter option for semicolon-based European CSV files.
Frequently Asked Questions
No. This tool runs entirely in your browser using JavaScript. Your CSV and JSON data is never sent to our servers, which makes it safe to use with sensitive or confidential data.
The first row is treated as the column headers by default. Fields containing commas, quotes, or line breaks should be wrapped in double quotes, following the standard RFC 4180 CSV format. You can also choose a semicolon or tab delimiter for European-style CSV files.
The converter expects a JSON array of objects, where each object represents one row and its keys become the CSV column headers, e.g. [{"name":"Alice","age":30},{"name":"Bob","age":25}]. Nested objects and arrays are automatically flattened or stringified.
When converting JSON to CSV, the tool collects every unique key found across all objects to build the header row. Any object missing a particular key gets an empty value in that column, so no data is lost.