JSON Flatten — Nested to Dot-Notation

Flatten nested JSON objects into single-level key-value pairs using dot notation. Perfect for configuration, logging, and data analysis. 100% client-side.

JSON Input0 chars

Output—

Output:

🛡️Zero server logs. Flattening runs 100% inside your browser.

JSON Flatten — Nested to Dot-Notation

Flatten nested JSON objects into single-level key-value pairs using dot notation. Perfect for configuration, logging, and data analysis. 100% client-side.

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

How to Use

Paste your nested JSON data into the input editor.
Click Flatten to convert nested objects to dot-notation key-value pairs.
Copy the flattened output for use in configuration systems or data analysis pipelines.

Frequently Asked Questions

Questions about this tool? We've got answers.

How does the flattening work?

Nested properties are converted to dot-notation (e.g., user.address.city becomes user.address.city). Array items use bracket notation with indices (items[0]).

What about arrays?

Array elements are flattened with numeric indices in bracket notation (e.g., hobbies[0], hobbies[1]), making the structure fully addressable as flat key-value pairs.

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

23/23

Env

V8-Sandbox

Engine: Vitest RunnerUpdated: 2026/7/16 02:08:13📦 Download Test Datasets

PASSflattenJson should flatten benchmark data

PASSflattenJson should handle deep nesting

PASSflattenJson should handle simple object

PASSflattenJson should handle empty object

PASSflattenJson should handle flat array

PASSflattenJson should throw on empty input

PASSflattenJson should throw on invalid JSON

PASSflattenJson should throw on scalar input

PASSflattenJson should throw on string input

PASSJsonFlattenTool renders Flatten button

PASSJsonFlattenTool renders JSON Input and Flattened Output labels

PASSJsonFlattenTool shows Load URL button

PASSJsonFlattenTool renders two textareas

PASSJsonFlattenTool shows privacy strip

PASSJsonFlattenTool shows error toast on Flatten with empty input

PASSJsonFlattenTool shows Clear toast on Clear All click

PASSJSON Flatten Worker Standard flatten operations should flatten simple JSON object

PASSJSON Flatten Worker Standard flatten operations should flatten deeply nested JSON

PASSJSON Flatten Worker Standard flatten operations should propagate requestId correctly

PASSJSON Flatten Worker Boundary Conditions & Error Handling should return error for invalid JSON

PASSJSON Flatten Worker Boundary Conditions & Error Handling should return error for empty input

PASSJSON Flatten Worker Boundary Conditions & Error Handling should handle empty object gracefully

PASSJSON Flatten 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 flattening of simple JSON objects and deeply nested JSON structures.
Test: Introduced error validation for malformed JSON, empty inputs, and empty object handling.
Performance: Included large JSON (4MB+) stress benchmark with flatten throughput and memory telemetry.

1.0.02026-06-10

Feature: Initial release