How JSON to CSV conversion works
The converter expects a JSON array of flat objects. It collects all unique keys across every object to build the CSV header row, then iterates through each object to produce one row per entry. Values are placed under their corresponding column, and missing keys result in empty cells.
String values that contain commas, double quotes, or newlines are automatically wrapped in double quotes and escaped per the RFC 4180 CSV specification. Numeric and boolean values are written as-is.
Handling nested objects and arrays
CSV is a flat tabular format, so nested JSON structures need flattening. If an object contains a nested object, the converter typically serializes it as a JSON string within the CSV cell or uses dot-notation column headers (e.g., "address.city"). The exact behavior depends on the nesting depth.
For best results, flatten your JSON before converting or ensure your objects are single-level. If you have arrays within objects (like tags or categories), they will be serialized as bracketed strings in the CSV cell.
Privacy and local processing
The conversion runs entirely in your browser. Your JSON data is never sent to any server, stored, or logged. This is especially relevant when converting datasets that contain personal information like emails, addresses, or user records.
Nothing persists between sessions. Closing the tab discards all data immediately.
Practical tips for clean conversions
Ensure all objects in your array have consistent keys. If some objects have extra fields, those columns will be empty for other rows, which is valid CSV but can look confusing in a spreadsheet. Normalizing your data before conversion produces cleaner output.
If your target application (Excel, Google Sheets, a database import tool) has specific delimiter or encoding requirements, note that this tool produces standard comma-separated output with UTF-8 encoding. Most modern applications accept this format directly.
Frequently asked questions
Does the converter handle nested JSON?
Partially. Nested objects are serialized as JSON strings within CSV cells. For cleanest results, flatten your data to single-level objects before converting.
Is my data uploaded during conversion?
No. The entire conversion happens in your browser using JavaScript. Your data never leaves your device.
What if my objects have different keys?
The converter builds headers from the union of all keys across all objects. Objects missing a key will have an empty cell in that column.
Does it handle special characters in values?
Yes. Values containing commas, double quotes, or newlines are automatically quoted and escaped per RFC 4180, the CSV standard.
Can I convert a single JSON object instead of an array?
The tool expects an array of objects, where each object becomes one row. A single object would produce just one data row. Wrap it in brackets [{}] to make it a valid input.