JSON to CSV Converter — Convert JSON to CSV Online Free
Paste JSON Array
Drop file to load
Processed locally in browser
What is the JSON to CSV Converter?
Convert JSON to CSV instantly — this free, browser-based JSON to CSV converter transforms arrays of JSON objects into tabular Comma-Separated Values (CSV) format entirely inside your browser, without uploading your data to any server. It is designed for developers who need to export API responses, NoSQL database dumps, or JSON data files into a format that business analysts, data scientists, or spreadsheet applications can immediately consume.
The tool reads your JSON array, collects all unique keys across all objects to construct the CSV header row, and then maps each object’s values into the corresponding columns. Quoted strings, commas within values, and special characters are automatically escaped to produce valid RFC 4180-compliant CSV output. You can control the header casing — keeping the original key names, converting to camelCase, or converting to snake_case — to match the conventions expected by your target system.
Because the conversion runs entirely in the browser’s JavaScript engine, your JSON data never leaves your machine. This matters most when the data contains user records, financial information, internal API responses, or proprietary business data that should not pass through a third-party server.
How to Use the JSON to CSV Converter
- Paste your JSON array into the left input panel. The tool expects an array of objects, formatted as
[{...}, {...}]. Each object will become one row in the CSV. The tool is flexible — objects can have different keys and varying numbers of fields. - Set your Header Casing option in the options bar. Choose Original to keep keys exactly as they appear in your JSON, camelCase for JavaScript conventions, or snake_case for Python and database imports.
- The CSV output appears instantly in the right panel. The first row contains the column headers derived from your JSON keys. Each subsequent row corresponds to one JSON object, with values in the correct columns and empty cells where a key is absent.
- Review the output to confirm the column headers are correct and values are properly quoted. CSV values that contain commas or double quotes are automatically wrapped in quotes and escaped, so the output is safe to import into any spreadsheet application.
- Copy or download the CSV. Click Copy to paste the CSV directly into Excel or Google Sheets, or click Download to save a
.csvfile. For Excel-specific output with proper data typing, use our JSON to Excel converter instead.
Common Use Cases
Exporting NoSQL database records to spreadsheets: When a business team needs to review MongoDB, Firestore, or DynamoDB data in Excel or Google Sheets, the JSON documents from these databases must first be converted to CSV. Paste the exported JSON array here to get a download-ready CSV file without writing a custom export script or changing your backend code.
API response data to Excel for stakeholders: REST API responses frequently return arrays of JSON objects — user records, order histories, analytics events, transaction logs. When non-technical stakeholders request this data in spreadsheet form, paste the API response JSON here for instant conversion. For complex nested responses, run the JSON through our JSON Flattener first.
Migrating data between systems: Data migration projects often involve extracting records from a source system (as JSON) and importing them into a destination (which may accept CSV as the import format). This converter bridges the gap, letting you convert JSON exports from your source system into the CSV format expected by the destination’s import tool.
Building test data for spreadsheet applications: When developing features that interact with CSV file uploads or spreadsheet imports, you need realistic test CSV files. If your test data is defined as JSON fixtures, paste the array here to produce test CSV files that match the format your application will encounter in production.
Log and event data analysis: Modern observability platforms (DataDog, Splunk, CloudWatch) can export events and log records as JSON. When running ad-hoc analysis on a subset of exported events, converting the JSON export to CSV lets you use Excel’s filtering, sorting, and pivot table features to quickly identify patterns and anomalies.
How Browser-Only Processing Works for This Tool
The conversion logic runs as a JavaScript function inside your browser. The function first validates that your input is a JSON array. It then iterates over all objects in the array and uses a JavaScript Set to collect every unique key across all objects — this builds the complete set of column headers. The header row is written first.
For each object in the array, the function maps its values to the corresponding column positions. Values that contain commas, double quotes, or newlines are wrapped in double quotes and any embedded double quotes are escaped with a second double quote (the standard CSV escaping convention). The complete CSV string is assembled and written to the output panel.
No data is sent to any server at any point. You can confirm this by opening DevTools (F12), going to the Network tab, and pasting JSON while watching the request log. You will see no outbound requests carrying your data.
Example Input
[
{ "id": 1, "name": "Alice", "role": "admin" },
{ "id": 2, "name": "Bob", "role": "user" }
]Example Output
id,name,role
1,Alice,admin
2,Bob,userWhy use this offline converter?
Exporting JSON database dumps or API responses often involves sensitive user data. This browser-only converter guarantees your records are processed locally and never transmitted across the internet.
Frequently Asked Questions
How does the JSON to CSV conversion work?▼
The converter expects an array of JSON objects. It scans all the objects to extract every unique top-level key to use as CSV column headers, then maps each object's values to the corresponding column, automatically escaping quotes and commas to produce valid CSV. The result is a correctly formatted CSV file where each JSON object becomes one row and each key becomes a column.
What happens to nested JSON objects?▼
By default, nested objects are serialized as text strings within their cell (e.g., a nested address object becomes the string '{"city":"London"}'). For deeply nested data where you need individual columns for each nested field, we recommend using our JSON Flattener tool first to normalize the structure into a flat object, then converting the flattened JSON to CSV for clean tabular output.
Is this safe for sensitive production data?▼
Yes. All conversion logic runs entirely on your local machine inside the browser's JavaScript engine. No data is ever uploaded to a server — there are no network requests, no server-side processing, and no data retention. This makes it safe for API responses containing user records, database exports, financial data, and any other sensitive content you need to convert.
Can I control how the CSV column headers are named?▼
Yes. The options bar above the editor lets you choose the header casing applied to your JSON keys. You can keep the original key names as-is from your JSON, convert to camelCase for consistency with JavaScript conventions, or convert to snake_case for Python and database-oriented workflows. The headers in the generated CSV will reflect your chosen casing.
What if my JSON objects have different keys?▼
The converter scans all objects in the array and collects every unique key across all objects to build the complete set of column headers. If some objects are missing certain keys, those cells are left empty in the CSV. This handles real-world API responses where not every record has every field — you get all columns present in any record, with empty cells where values are absent.