JSON Unflatten — Dot-Notation to Nested

Restore flattened JSON objects back to their original nested structure. Inverse of JSON flattening with dot-notation parsing. 100% client-side.

JSON Input0 chars
Output—
Output:
🛡️Zero server logs. Unflattening runs 100% inside your browser.
🛠️Developer Tool Belt
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JSON Unflatten — Dot-Notation to Nested

Restore flattened JSON objects back to their original nested structure. Inverse of JSON flattening with dot-notation parsing. 100% client-side.

🔒 Client-side only⚡ Web Worker processing🌐 Works offline🛡️ Zero server logs

How to Use

  1. Paste your flattened key-value pairs (dot notation) into the input editor.
  2. Click Unflatten to restore the original nested JSON structure.
  3. Copy the reconstructed nested JSON for use in your application.

Frequently Asked Questions

Questions about this tool? We've got answers.

What notation is supported?

Standard dot notation (user.address.city) and bracket array notation (items[0].name) are both supported for parsing and restoration.

Does it handle edge cases?

Yes. The tool handles mixed arrays and objects, special characters in keys, and deep nesting levels without stack overflow.

Is my data sent to a server?

No. All processing runs 100% inside your browser via a Web Worker.

Automated E2E Test Suite Logs

Our build systems validate edge-case processing under extreme conditions before each deployment.

Stability
100.0%
Passed
22/22
Env
V8-Sandbox
Engine: Vitest RunnerUpdated: 2026/6/11 00:18:12📦 Download Test Datasets
PASSunflattenJson should restore flat benchmark data to nested structure
PASSunflattenJson should handle deep nesting
PASSunflattenJson should handle simple flat object
PASSunflattenJson should handle empty object
PASSunflattenJson should throw on empty input
PASSunflattenJson should throw on invalid JSON
PASSunflattenJson should throw on array input
PASSunflattenJson should throw on scalar input
PASSJsonUnflattenTool renders Unflatten button
PASSJsonUnflattenTool renders Flattened JSON and Nested Output labels
PASSJsonUnflattenTool shows Load URL button
PASSJsonUnflattenTool renders two textareas
PASSJsonUnflattenTool shows privacy strip
PASSJsonUnflattenTool shows error toast on Unflatten with empty input
PASSJsonUnflattenTool shows Clear toast on Clear All click
PASSJSON Unflatten Worker Standard unflatten operations should unflatten flat keyed JSON
PASSJSON Unflatten Worker Standard unflatten operations should unflatten with deep nested keys
PASSJSON Unflatten Worker Standard unflatten operations should propagate requestId correctly
PASSJSON Unflatten Worker Boundary Conditions & Error Handling should return error for invalid JSON
PASSJSON Unflatten Worker Boundary Conditions & Error Handling should return error for empty input
PASSJSON Unflatten Worker Boundary Conditions & Error Handling should handle empty object gracefully
PASSJSON Unflatten Worker Performance Benchmark should process large JSON within acceptable limits
⏱️ 0.18ms📦 1.5KB🎚️ Max Nesting: 3🌿 AST Nodes: 48🛡️ V8 Heap: Healthy
$ codecaven-validator --scope=tool● CLUSTER COMPLIANT

Tool Changelog & Updates

1.0.02026-06-10
  • Feature: Initial release