Unflatten JSON
Reconstruct nested JSON structures from flat dot-notation key-value pairs. Fast, free, and fully client-side.
Input source
Result / Output
How the Unflatten JSON Works
Reconstructs nested hierarchical JSON objects from flattened dot-notation key-value maps.
Usage Example
Input: `{"user.name": "Alice", "user.age": 30}` → Output: `{"user": {"name": "Alice", "age": 30}}`.
Frequently Asked Questions
Does unflattening support array indexes?
Yes, keys with numeric bracket indices (e.g. `items[0].id`) are restored as proper JSON arrays.
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See all JSON tools.