SupportQuick overview
Clean, transform, and validate content with JSON ↔ CSV in a fast private browser workflow.
Free Online JSON ↔ CSV Converter with Flattening
The ultimate tool to convert JSON to CSV and CSV to JSON. Features built-in support for flattening nested objects, custom separators, and smart column detection. Process large datasets securely in your browser.
Mastering JSON & CSV Data Transformation
Why use our JSON ↔ CSV Converter?
Handling data between different systems often requires switching between JSON (the language of APIs) and CSV (the language of spreadsheets). Our converter is designed to bridge this gap with professional-grade features like recursive flattening and smart column mapping, all while keeping your data 100% private on your device.
Core Transformation Features
Recursive Flattening
Automatically transform nested JSON objects into flat CSV columns using dot notation or your preferred separator.
Smart Column Detection
Our engine scans your entire dataset to extract every unique key, ensuring no data is lost during the conversion process.
Array Management
Choose how to handle arrays: join them into a single cell or keep them as stringified representations for further processing.
Instant Data Preview
See your converted data in a spreadsheet-style table before downloading, allowing for quick verification of results.
How to Convert and Flatten Your Data
- Select Direction: Use the toggle to choose between JSON to CSV or CSV to JSON conversion.
- Input Data: Paste your code directly or drag and drop your file into the upload zone.
- Configure Flattening: If converting JSON, enable "Flatten Nested Objects" and specify your separator (e.g., ".", "_", or "-").
- Download & Export: Review the live preview and click "Download CSV" or "Copy to Clipboard" to save your work.
Privacy & Security Commitment
At BrainyTools, we believe your data should stay yours. Unlike other online converters that upload your files to their servers, our tool processes everything locally in your browser. Your sensitive API responses or customer lists never leave your computer, making it the safest choice for developers and analysts alike.
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