Efficient JSON Mapping & Renaming Tool
MapJSON provides a powerful, secure, and purely client-side solution for developers who need to restructure JSON data quickly. Whether you are migrating between API versions, cleaning up data for a frontend application, or simply needing to rename keys to follow camelCase conventions, MapJSON streamlines the process securely within your browser.
Why Rename or Map JSON Fields?
Data formats rarely match perfectly between systems. A legacy backend might send user_id (snake_case), while your modern React frontend expects userId (camelCase). Manually finding and replacing text is error-prone and tedious. Mapping allows you to define explicit transformation rules, ensuring data integrity and preventing runtime errors caused by mismatched keys.
100% Client-Side Privacy
Unlike other online formatters that upload your data to a remote server for processing, MapJSON executes all transformations locally in your browser using JavaScript. This means your sensitive JSON data—whether it contains customer info, API keys, or internal configurations—never leaves your device. It is currently one of the safest ways to manipulate JSON online.
How to Use the MapJSON Tool
Paste Your Input
Copy your raw JSON data and paste it into the left-hand editor panel. The tool will automatically validate your input.
Map Your Fields
In the center panel, you will see a list of all detected keys. Type a new name to rename a specific field, or use the dropdown to "Ignore" fields you don't need in the output.
Export Result
The right-hand panel updates in real-time. Once satisfied, click "Copy to Clipboard" or "Download JSON" to save your transformed file.
Key Features
- Instant real-time preview
- Dual-pane mapping interface
- Privacy-focused (Zero-server)
- Smart field detection
- Ignore/Exclude specific fields
- One-click copy & download