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.

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

Paste your flattened key-value pairs (dot notation) into the input editor.
Click Unflatten to restore the original nested JSON structure.
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: 2026/7/16 02:08:13📦 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

v1.2.02026-06-12

UX: Updated About descriptions, How-to guides, and FAQ sections with detailed multi-language content.
UX: Added Load URL button via shared LoadUrlModal component for remote JSON loading.
Fix: Fixed i18n key names to match component usage — corrected "convert" to "generate"/"flatten"/"unflatten"/"merge" as appropriate.

1.1.02026-06-11

Feature: Added Web Worker thread-isolated test suite covering unflattening of flat keyed objects and deeply nested key structures.
Test: Introduced error validation for malformed JSON, empty inputs, and empty object handling.
Performance: Included large flat JSON (4MB+) stress benchmark with dot-notation key expansion and memory telemetry.

1.0.02026-06-10

Feature: Initial release