JSON Unflattener
Rebuild nested JSON objects from a flat object that uses dot-separated key paths.
- No login
- Free to use
- Processes locally
- No files uploaded
Try the JSON Unflattener
Processed locally in your browser
Your input and generated output are processed locally and are not sent to our servers for tool execution.
Examples
Basic object
{
"product": "UtilityKit",
"active": true,
"version": 2
}{
"product": "UtilityKit",
"active": true,
"version": 2
}Nested API-style payload
{
"user": {
"id": "usr_42",
"email": "ada@utilitykit.store",
"roles": ["editor", "billing"]
},
"meta": { "region": "in", "trial": false }
}{
"user": {
"id": "usr_42",
"email": "ada@utilitykit.store",
"roles": ["editor", "billing"]
},
"meta": { "region": "in", "trial": false }
}Features
- Validate and format structured JSON
- Inspect nested objects and arrays
- Copy or download cleaned JSON
- Works with realistic API-sized payloads in-browser
- No account required
How to use JSON Unflattener
- Paste a flat JSON object and run the unflattener to restore nested object structure.
Use cases
- Restore flattened exports
- Build nested configuration
- Reverse JSON flattening
Technical reference
| Property | Supported |
|---|---|
| Input | JSON text (UTF-8) |
| Output | Formatted / validated / transformed JSON or text |
| Execution | 100% client-side in a modern browser |
| Account | Not required |
| Upload destination | None — Open local file stays in-browser |
| Output actions | Copy and download when available |
Common errors & troubleshooting
Unexpected token / trailing comma
Cause: JSON does not allow trailing commas after the last property.
Fix: Remove the extra comma, or fix quotes, then run validation again.
Unclosed object or array
Cause: A `{`, `[`, or quote was opened without a matching closer.
Fix: Check brace balance and string quotes, then re-run.
Empty input
Cause: The editor is empty.
Fix: Paste JSON or use Load example before running JSON Unflattener.
Privacy and security
- Your input and generated output are processed locally and are not sent to our servers for tool execution.
- Opening a local file uses the browser File API; the file is not uploaded to UtilityKit.
- We may collect anonymous product analytics (for example page views). Tool contents are not included in those events.
- JSON Unflattener runs in your browser; extremely large inputs may be slow or limited by device memory.
- Results depend on your browser’s JavaScript engine and available APIs.
Frequently asked questions
Can JSON Unflattener rebuild nested objects?
Rebuild nested JSON objects from a flat object that uses dot-separated key paths. Paste a flat JSON object and run the unflattener to restore nested object structure.
Can I use this tool to restore flattened exports?
Yes. This tool is designed for workflows such as restore flattened exports, build nested configuration, reverse json flattening.
Related tools
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Open JSON FormatterJSON Validator
Check JSON syntax and get a clear message when the input is invalid.
Open JSON ValidatorJSON Minifier
Remove unnecessary whitespace from JSON without changing its data.
Open JSON MinifierJSON Tree Viewer
Browse nested JSON as a collapsible tree instead of raw text.
Open JSON Tree ViewerJSON Diff Checker
Compare two JSON values and list added, removed, and changed paths.
Open JSON Diff CheckerJSON Key Sorter
Sort object keys alphabetically throughout a JSON document.
Open JSON Key SorterJSON Escape Tool
Escape text for safe use inside a JSON string value.
Open JSON Escape ToolJSON Unescape Tool
Convert JSON escape sequences back into readable text.
Open JSON Unescape ToolRelated guides
- Browse all JSON Utilities tools
- Explore the full UtilityKit catalogue
- How UtilityKit maintains tool documentation
- Privacy: how local processing works
UtilityKit on utilitykit.store — Everything You Need. One Utility Kit.