Free Online JSON to CSV Converter
Convert a JSON array of objects to CSV format instantly. Auto-detects column headers from object keys and generates downloadable CSV output.
How the JSON to CSV Converter Works
This tool converts a JSON array of objects into CSV (Comma-Separated Values) format. It automatically extracts all unique keys from the objects to create the header row. Each object becomes a row in the CSV, with values properly escaped and quoted when they contain commas, newlines, or double quotes.
JSON Input Format
The input must be a valid JSON array containing objects. Each object should have string keys and simple values (strings, numbers, booleans). Nested objects or arrays within the JSON objects will be converted to their string representation. All objects do not need to have the same keys — missing keys will result in empty CSV cells.
CSV Escaping and Formatting
The converter follows RFC 4180 conventions for CSV formatting. Fields containing commas, double quotes, or newlines are enclosed in double quotes. Double quotes within a field are escaped by doubling them. This ensures the output is compatible with spreadsheet applications like Excel, Google Sheets, and LibreOffice Calc.
Frequently Asked Questions
What JSON format does it accept?
The input must be a JSON array of objects, for example: [{"name":"John"},{"name":"Jane"}]. It cannot convert a single object, nested arrays, or primitive values. Each object in the array becomes one CSV row.
What if objects have different keys?
The converter collects all unique keys from all objects to create the header row. If an object is missing a key, the corresponding CSV cell will be empty. This handles heterogeneous JSON arrays gracefully.
How are nested objects handled?
Nested objects and arrays are converted to their JSON string representation in the CSV cell. For flat CSV output, you should flatten your JSON structure before converting.
Can I open the output in Excel?
Yes. The CSV output follows standard formatting with proper quoting and escaping. Copy the output, save it as a .csv file, and open it in Excel, Google Sheets, or any spreadsheet application.
Is there a size limit?
Processing happens in your browser, so the limit depends on your device memory. JSON arrays with several thousand objects work well on modern devices. For very large datasets, consider using a command-line tool.