JSON Test Data Generator — Build Custom API Payloads Instantly
Generate structured JSON data including names, emails, addresses and custom fields for API testing, database seeding and UI development.
Select Identity Fields
Toggle the fields you want included in the generated JSON output
Password Configuration
Configure the generated password complexity and length
Custom JSON Fields
Add your own fields to the JSON output — orderId, createdAt, amount or any key you need. Max 10 custom fields.
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Paste JSON → Generate Data
Paste any sample JSON payload and generate realistic fake data automatically.
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What Does This JSON Test Data Generator Do?
This tool generates structured, realistic JSON data on demand — no libraries, no code, no setup required. Select from built-in identity fields like name, email and address, configure password complexity, and add your own custom fields with specific types — strings, numbers, UUIDs, dates and more. The output is clean, formatted JSON ready to paste directly into your API client, Postman collection, test script or database seed file.
Who is This Tool For?
API Developers
Build realistic request payloads for REST API testing without manually crafting JSON every time.
QA Engineers
Generate fresh unique test data for every test run — no stale data, no conflicts between test cases.
Database Developers
Seed development and staging databases with realistic structured data that matches your schema.
Frontend Developers
Populate UI components and prototypes with realistic looking data instead of lorem ipsum placeholders.
Test Automation
Generate test fixtures and mock data for automated testing pipelines and CI/CD workflows.
Privacy Compliant
All generated data is completely fictional — GDPR compliant, no real personal data involved.
How to Use This Tool
- Select which identity fields to include in your JSON output
- Configure password complexity if password field is selected
- Add custom fields — orderId, amount, createdAt, transactionId etc.
- Click Generate JSON — structured output appears instantly
- Copy JSON and paste into Postman, your test script or database
Custom Field Types Supported
| Type | Output Example | Use Case |
|---|---|---|
| String | "lorem ipsum dolor" | Description, notes, comments |
| Number | 742 | Age, quantity, score, ID |
| Number (Decimal) | 149.99 | Price, amount, percentage |
| UUID | "a1b2c3d4-..." | orderId, transactionId, sessionId |
| "user@example.com" | Secondary email, contact email | |
| Past / Future Date | "2024-03-15" | createdAt, expiryDate, dob |
| Past / Future DateTime | "2024-03-15T10:22:00Z" | timestamps, audit logs, events |