Free online bidirectional JSON↔CSV converter tool. Convert JSON arrays to CSV tables or CSV data to JSON arrays. Supports nested object auto-flattening, custom delimiters and quote characters. All processing runs in your browser — no data is uploaded.
Client-side·Zero Upload·Large File ReadyClick "Convert" to see table preview
JSON (JavaScript Object Notation) and CSV (Comma-Separated Values) are two of the most widely used data interchange formats. This tool provides bidirectional conversion, allowing you to switch seamlessly between them.
Converts JSON arrays to CSV format — each object becomes a row, and object keys become column headers. Supports auto-flattening of nested objects and custom delimiter/quote characters.
Converts CSV tabular data to JSON arrays — the first row is used as keys (headers), and each subsequent row becomes a JSON object. Supports auto-detection of delimiters, quoted fields, and escape characters.
This tool supports Arrays of Objects (the most common structured data format). Each object represents a record, and object keys become CSV column headers. Nested objects can be flattened using the "Flatten nested" option.
The tool automatically handles standard CSV quoting — fields containing delimiters, newlines, or quotes are properly wrapped. Double-quote escaping (two quotes for a literal quote) is fully supported.
No. All conversion processing runs entirely in your browser. Your data never leaves your computer, making it safe for sensitive information.
Processing is limited by browser memory, typically handling hundreds of thousands of records. For very large files, consider batch processing. You can load .json, .csv, and .tsv files directly via the file upload button.
Yes. You can customize the column delimiter (default: comma) and quote character (default: double quote). For example, set tab delimiter for TSV format, or use single quotes.