JSON Mock Generator — Generate Realistic Test Data

Generate realistic mock JSON data from a JSON Schema using Faker. Perfect for prototyping, testing, and populating demo environments with lifelike data. 100% client-side.

JSON Schema0 chars

Output—

Output:

🛡️Zero server logs. Mock generation runs 100% inside your browser.

JSON Mock Generator — Generate Realistic Test Data

Generate realistic mock JSON data from a JSON Schema using Faker. Perfect for prototyping, testing, and populating demo environments with lifelike data. 100% client-side.

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

How to Use

Define your JSON Schema in the input editor (or use the default template).
Adjust the count and click Generate Mock to create realistic test data.
Copy the generated data for testing, demos, or API development.

Frequently Asked Questions

Questions about this tool? We've got answers.

What data does the generator produce?

The generator uses Faker.js to produce realistic data including names, emails, phone numbers, addresses, and more — all matching your schema structure and type constraints.

Can I control the output size?

Yes. Use the count slider to control how many objects to generate. You can also set minimum/maximum values for arrays and strings in the schema itself.

Is my schema sent to any server?

No. All generation 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

28/28

Env

V8-Sandbox

Engine: Vitest RunnerUpdated: 2026/6/11 00:18:12📦 Download Test Datasets

PASSgenerateMockData should generate data matching the schema structure

PASSgenerateMockData should generate integer for integer type

PASSgenerateMockData should generate string for string type

PASSgenerateMockData should generate boolean for boolean type

PASSgenerateMockData should handle nested objects

PASSgenerateMockData should handle benchmark schema with all types

PASSgenerateMockData should generate values from enum when specified

PASSgenerateMockData should generate different values on each call

PASSgenerateMockData should throw on empty input

PASSgenerateMockData should throw on invalid JSON

PASSgenerateMockData should throw on schema without type or properties

PASSJsonMockGeneratorTool renders Generate Mock button

PASSJsonMockGeneratorTool renders Regenerate button

PASSJsonMockGeneratorTool renders JSON Schema and Generated Data labels

PASSJsonMockGeneratorTool renders two textareas

PASSJsonMockGeneratorTool shows privacy strip

PASSJsonMockGeneratorTool shows error toast on Generate with empty input

PASSJsonMockGeneratorTool shows Clear toast on Clear All click

PASSJSON Mock Generator Worker Standard schema processing should generate mock data from simple schema

PASSJSON Mock Generator Worker Standard schema processing should handle nested schema with arrays

PASSJSON Mock Generator Worker Standard schema processing should generate from benchmark schema

PASSJSON Mock Generator Worker Standard schema processing should generate enum values from enum-schema

PASSJSON Mock Generator Worker Standard schema processing should propagate requestId correctly

PASSJSON Mock Generator Worker Standard schema processing should generate different output on successive calls

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

PASSJSON Mock Generator Worker Boundary Conditions & Error Handling should return error for invalid JSON schema

PASSJSON Mock Generator Worker Boundary Conditions & Error Handling should return error for empty object input

PASSJSON Mock Generator Worker Performance Benchmark should process benchmark schema 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