Rebuilds nested JSON from flat dot/bracket path keys.
JSON Unflatten rebuilds nested JSON from a flat object whose keys are dot and bracket paths. Paste a flat map like {"a.b[0].c": 1} and the tool expands it back into nested objects and arrays. It is handy whenever you have config values, query results, or form data stored as path-to-value pairs and need the original nested structure.
No. The tool runs entirely in your browser and nothing is uploaded. Your JSON is parsed and rebuilt locally, so no data leaves your device.
It splits keys on dots for object properties and on [n] for numeric array indices, so a key like a.b[0].c becomes {"a":{"b":[{"c":...}]}}. Numeric segments in brackets create arrays; everything else creates object keys.
A single flat JSON object whose keys are paths and whose values are the leaf values. If the input is not an object (for example an array or a primitive), it reports that the input must be a flat JSON object of path-to-value pairs.
The first key's leading token determines the root type: if it is a numeric bracket index the root becomes an array, otherwise it becomes an object. An empty input object produces {}.
Yes. The rebuilt JSON is returned with two-space indentation so it is easy to read and copy.