What is JSON and why generate random data?

JSON (JavaScript Object Notation) is a lightweight data format used to structure and exchange information between systems. It's the standard format for web APIs, configuration files, and data storage. Random JSON generation with realistic dummy data is essential for testing applications, prototyping APIs, and creating sample datasets without exposing real user information.

Tool description

This Random JSON Generator creates realistic test data using Faker.js templates. Define your JSON structure with placeholders like {{person.firstName}} or {{internet.email}}, and the tool automatically fills them with appropriate dummy values. Generate single objects or arrays of multiple records for comprehensive testing.

Features

  • Template-based generation: Define custom JSON structures with Faker.js placeholders
  • Realistic dummy data: Access hundreds of Faker.js methods for names, emails, addresses, dates, and more
  • Multiple records: Generate arrays of objects by specifying the number of records
  • Live preview: See generated JSON instantly with proper formatting
  • Syntax highlighting: Code editor with JSON validation and error reporting
  • Method parameters: Support for Faker methods with parameters like {{number.int(1,100)}}

Examples

Template with placeholders:

{
  "id": "{{string.uuid}}",
  "name": "{{person.fullName}}",
  "email": "{{internet.email}}",
  "age": "{{number.int(18,80)}}",
  "city": "{{location.city}}"
}

Generated output:

{
  "id": "f47ac10b-58cc-4372-a567-0e02b2c3d479",
  "name": "John Smith",
  "email": "john.smith@example.com",
  "age": 34,
  "city": "New York"
}

Supported Faker.js categories

  • Person: firstName, lastName, fullName, jobTitle, gender, bio
  • Internet: email, url, domainName, username, password
  • Location: city, country, streetAddress, zipCode, latitude, longitude
  • Company: name, catchPhrase, industry, department
  • Phone: number, imei, imsi
  • Date: past, future, recent, birthdate, month, weekday
  • Commerce: product, price, productName, department
  • Lorem: word, words, sentence, paragraph, text
  • String: uuid, alpha, alphanumeric, numeric, sample
  • Finance: amount, creditCardNumber, bitcoinAddress, iban
  • Number: int, float, binary, octal, hex

Use Cases

  1. API Testing: Generate mock data for testing REST API endpoints and responses
  2. Database Seeding: Create realistic sample data for development databases
  3. UI Prototyping: Populate interfaces with dummy data during design phase
  4. Load Testing: Generate large datasets for performance and stress testing
  5. Documentation: Create example payloads for API documentation