JSON to CSV Converter Online Free — Convert JSON ↔ CSV Instantly
JSON ↔ CSV Converter converts JSON arrays to CSV spreadsheets and CSV files back to JSON objects. It handles nested JSON objects via dot notation flattening, auto-detects CSV delimiters, and infers data types for numbers and booleans. Convert in both directions and download as .json or .csv files. Everything runs in your browser — your data is never uploaded.
Frequently Asked Questions
How do I convert JSON to CSV?
Paste your JSON array into the input, select "JSON → CSV" direction, and the converter will automatically extract column headers from the JSON keys and produce a properly formatted CSV. Nested objects are flattened using dot notation (e.g., address.city becomes a column header).
What happens with nested JSON objects?
When the "Flatten nested objects" option is enabled, nested objects are expanded into dot-separated column names. For example, {"user": {"name": "Alice", "age": 30}} becomes two columns: user.name and user.age. If flattening is disabled, nested objects are serialized as JSON strings in the cell.
Does CSV to JSON support type inference?
Yes. When type inference is enabled, the converter automatically converts numeric strings to numbers ("30" → 30), boolean strings to booleans ("true" → true, "false" → false), and "null" strings to null values. Disable this option if you need all values to remain as strings.
What CSV delimiters are supported?
The converter supports comma (,), semicolon (;), tab, and pipe (|) as delimiters. When converting CSV to JSON, you can select Auto-detect and the converter will identify the delimiter from the first line of your CSV file.
Is my data sent to a server?
No. All JSON and CSV conversion happens entirely in your browser using vanilla JavaScript. Your data is never uploaded to any server and is never stored or logged. The tool works completely offline once the page has loaded.
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