JSON Unflattener
Reconstruct deeply nested JSON objects from flat dot-notated key-value pairs.
How It Works & Processing Standards
Reconstruct deeply nested JSON objects from flat dot-notated key-value pairs.
Your input data is never sent to any server and is securely processed on your device.
Current Limits
- Desktop max file size: 50MB
- Mobile max file size: 20MB
JSON Unflattener is a 100% free, browser-based online utility. All calculations and file conversions run locally inside your browser (Local-First) without sending data to remote servers, keeping your documents and inputs strictly private.
How to Use JSON Unflattener
- 1Paste Flat JSONPaste a JSON object with dot-separated keys.
- 2Select SeparatorConfirm the key delimiter (default dot).
- 3Generate Nested JSONView and copy the restored nested JSON structure.
Examples
Unflatten Object
Input: {"user.profile.name": "Alice", "user.profile.city": "Seoul"}
Result: {
"user": {
"profile": {
"name": "Alice",
"city": "Seoul"
}
}
}
Common Use Cases
- Restoring nested configurations from flattened environment variables
- Reconstructing full objects from flattened database rows or key-value stores
- Processing query string form parameters into structured JSON bodies
Frequently Asked Questions (FAQ)
How are numerical keys handled?
Sequential numeric keys (e.g. items.0, items.1) are automatically reconstructed into JSON arrays.