JSON to CSV & CSV to JSON Converter
Transform JSON arrays into clean CSV spreadsheets and vice-versa. Automatically flatten nested objects, customize delimiters, preview interactive tables, and export without server uploads.
Conversion Mode
How to Convert JSON to CSV in 3 Steps
- Paste Data or Upload File: Paste your JSON array (or CSV text) into the editor, or upload a
.jsonor.csvfile from your computer. - Configure Formatting: Select your preferred delimiter (comma, semicolon, tab, pipe) and choose whether to flatten nested structures.
- Inspect & Download: Examine the live interactive table preview, copy the transformed code with one click, or download your file.
Data Type Transformation Reference
How complex JavaScript / JSON structures are mapped to standard tabular columns:
| JSON Structure | Sample Input | CSV Column Output | Handling Rules |
|---|---|---|---|
| Flat Key-Value | {"name": "Alice", "age": 30} | name,age Alice,30 | Mapped directly to standard columns |
| Nested Object | {"user": {"city": "Boston"}} | user.city Boston | Dot-notation flattening (e.g. user.city) |
| Array of Primitives | {"tags": ["red", "blue"]} | tags "["red","blue"]" | JSON stringified and wrapped in quotes |
| Strings with Commas | {"company": "Smith, Jones & Co."} | "Smith, Jones & Co." | RFC 4180 compliant quotation escaping |
| Null or Undefined | {"middle": null} | middle | Exported as clean empty string without errors |
Frequently Asked Questions
How does this converter handle nested JSON objects?▼
When the 'Flatten Nested Objects' option is checked (enabled by default), nested sub-objects are automatically transformed into dot-notation column names. For example, {'user': {'address': {'city': 'Austin'}}} becomes a single table header named user.address.city.
Can I convert CSV back into JSON format?▼
Yes! Click the 'CSV to JSON' button in the toolbar. Paste your comma-separated or tab-separated text (or upload a .csv file), and the tool will instantly output formatted, indented JSON with automatic type inference for numbers and booleans.
Is there a limit on file size or number of records?▼
Because all transformation is handled by PapaParse in your local browser memory, you can easily convert tens of thousands of rows within seconds without hitting cloud gateway timeouts or rate limits.
Does this tool work with Excel and European CSV files that use semicolons?▼
Yes! In many European countries, Excel exports CSVs with semicolons (;) instead of commas. Simply change the 'Delimiter' dropdown to 'Semicolon (;)' to parse or generate European-formatted files seamlessly.
Are my spreadsheets or JSON datasets uploaded to any server?▼
Never. The conversion executes 100% in your local web browser. Your confidential customer emails, financial ledgers, and database dumps remain completely private.
How are quotation marks and commas escaped?▼
The converter strictly follows the RFC 4180 standard. Any field containing commas, line breaks, or quotation marks is automatically wrapped in double quotes, with internal quotes escaped as double-quotes (" ").
Can I download the output as a physical .csv or .json file?▼
Yes! Click the 'Download' button above the output pane to immediately save a UTF-8 encoded .csv or .json file directly to your downloads folder.
Features & Privacy
- ✓100% In-Browser: Zero datasets uploaded to servers.
- ✓RFC 4180 Compliant: Escapes commas, quotes, and newlines.
- ✓Interactive Table Preview: Instant visualization of rows.
- ✓Bidirectional: Converts both JSON→CSV and CSV→JSON.