JSON - CSV Converter
Convert between JSON and CSV formats instantly. Handles nested objects and arrays. Runs entirely in your browser.
JSON to CSV Conversion: A Developer's Guide
Converting between JSON and CSV is one of the most common data transformation tasks developers face. JSON is the standard for APIs and web applications, while CSV is the universal format for spreadsheets, databases, and data analysis tools like Excel, Google Sheets, and Pandas.
Key Features
- Nested object flattening — Converts
{"address": {"city": "NYC"}}to a flataddress.citycolumn using dot notation - Array handling — Arrays are joined with semicolons or serialized, preserving all data
- Proper CSV escaping — Values containing commas, quotes, or newlines are properly quoted per RFC 4180
- Custom delimiters — Support for comma, semicolon, and tab-separated formats
- CSV to JSON reverse conversion — First row becomes keys, with auto-detection of numbers and booleans
- Table preview — See your data in a formatted table before downloading
Common Use Cases
- API data export — Convert API JSON responses to CSV for analysis in Excel or Google Sheets
- Database migration — Transform JSON documents to CSV for relational database import
- Data science workflows — Prepare JSON datasets as CSV for Pandas, R, or Jupyter notebooks
- Reporting — Convert JSON logs or analytics data to CSV for stakeholder reports
- Spreadsheet import — Turn JSON config or data files into editable spreadsheets
Frequently Asked Questions
Nested JSON objects are flattened using dot notation for column headers. For example, {"address": {"city": "London"}} becomes a column named "address.city" with the value "London". Deeply nested arrays are serialized as JSON strings within the CSV cell.
No. All conversion happens entirely in your browser using JavaScript. Your JSON and CSV data never leaves your device, making this tool safe for sensitive datasets, API responses, and proprietary information.
Yes, this tool supports bidirectional conversion. Paste or upload CSV data and convert it to a JSON array of objects, where each row becomes an object and the header row defines the property names.
The converter collects all unique keys across all objects to build the CSV header row. Objects missing a particular key will have an empty value in that column. This ensures no data is lost during conversion.
Since processing runs in your browser, the limit depends on your device's available memory. Most modern devices handle files up to several megabytes without issues. For very large datasets (100 MB+), consider using command-line tools like jq or Python's pandas library.