ENDPOINTS
1 endpoint
Ready to generate
Define your endpoints and click Generate Mock// define endpoints and get realistic mock JSON output
Define REST API endpoints visually and generate realistic mock JSON responses instantly. Perfect for frontend development, testing, and prototyping without a backend.
Ready to generate
Define your endpoints and click Generate MockAdd one or more REST API endpoints. Set the HTTP method, path, and number of mock items to return.
Add fields to each endpoint. Choose from types like uuid, name, email, datetime, boolean, array, and more.
Click Generate Mock to get realistic JSON. Copy to clipboard or download as a .json file.
The API Mock Generator lets you define REST API endpoints with custom field schemas and instantly generate realistic mock JSON responses — no backend needed. Ideal for frontend developers building against an API that doesn't exist yet.
A mock API simulates the behavior of a real API by returning realistic fake data. It lets frontend developers build and test their UI without waiting for the backend to be ready, making development faster and more parallel.
The generator supports GET, POST, PUT, PATCH, and DELETE. Each method returns an appropriate response: GET returns a list with pagination metadata, POST/PUT/PATCH return the created or updated resource, and DELETE returns a success message.
Yes. When you add a field with the type "array" or "object", you can add sub-fields to define the nested schema. Arrays will contain 2–4 randomly generated items matching the sub-schema.
Yes. The generator uses smart inference — if you name a field "email" or "avatar_url" without specifying a type, it will automatically use realistic email addresses or image URLs respectively. This applies to common patterns like "id", "created_at", "price", "is_active", etc.
You can define up to 10 endpoints in a single generation request. Each endpoint can have its own method, path, and unique field schema, letting you mock an entire REST API surface in one go.
Absolutely. Download the JSON file and use it as fixture data, seed data for a mock server like json-server, or import it directly into your tests. The data is fully client-side generated and not stored anywhere.
For GET requests, this controls how many records appear in the mock response's data array. POST/PUT/PATCH always return a single item. DELETE always returns a success confirmation regardless of this setting.
The schema definition is sent to our server to generate the mock data, but neither the schema nor the response is stored. No account or sign-up is required, and all data is discarded immediately after the response is sent.
Modern frontend development almost always starts before the backend API is ready. Whether you're working in a team with separate frontend and backend developers, prototyping a new product, or writing automated tests, waiting for a live API creates unnecessary bottlenecks. The API Mock Generator solves this by letting you define your API endpoints and schema in minutes, then instantly generating realistic, structured JSON mock data you can use right away.
Mock API data is realistic-looking fake data that mirrors the structure of your real API responses. Instead of connecting to a live database, your frontend code consumes pre-generated JSON that has the same fields, types, and shape as the real thing. This lets you build out UI components, write unit and integration tests, and demonstrate features in staging environments — all without a working backend.
The key difference between mock data and random garbage is realism. A good mock API generator produces values that look real: UUIDs in the right format, email addresses that follow the correct pattern, ISO 8601 timestamps, names that sound human, image URLs that actually resolve, and prices formatted as decimals. This tool does all of that automatically based on the field types and names you define.
The workflow has three steps. First, you define your endpoints — the HTTP method (GET, POST, PUT, PATCH, or DELETE) and the URL path (e.g., /api/users). Second, you build the schema for each endpoint by adding fields, choosing their names and types. Third, you click Generate and receive a full mock JSON response that you can copy or download.
For GET requests with multiple items, the response follows a common REST convention with a data array and a meta object containing pagination info (total, page, per_page). POST and PUT/PATCH responses return the created or modified single resource. DELETE responses return a simple success message — exactly what most REST APIs return in the real world.
The generator supports a wide range of field types, each producing contextually appropriate values:
uuid produces RFC 4122 v4 UUIDs; id also generates UUIDs by default.name, firstname, lastname, email, username, phone — all produce realistic values drawn from common name and domain pools.date (YYYY-MM-DD), datetime (ISO 8601), timestamp (Unix epoch integer).image, avatar, photo produce valid Picsum photo URLs for visual mockups.integer, float, price, decimal.boolean / bool produces true or false.string produces short lorem-style phrases; text and paragraph produce longer content.status, role, tag, category produce realistic enum-style values.address, city, country.array (with sub-schema) and object (with nested fields) let you build complex hierarchical responses.You don't always need to specify a type manually. The generator analyzes field names and infers the most appropriate type. A field named created_at automatically becomes a datetime; avatar_url becomes an image URL; is_active becomes a boolean; total_price becomes a decimal. This significantly speeds up schema definition for common API patterns.
Real-world APIs rarely return flat objects. User profiles contain nested address objects; order responses contain arrays of line items; post responses contain nested author objects. The API Mock Generator supports this with the array and object types, both of which accept sub-schemas. You can nest multiple levels deep to represent any complex response structure your API needs to produce.
Teams and developers reach for this tool in a variety of situations:
Once generated, you have two export options. The Copy All button places the entire JSON output on your clipboard, ready to paste into your code editor, Postman, Insomnia, or any mock server configuration. The Download button saves a mock-api.json file to your device. This file can be dropped directly into tools like json-server or MSW (Mock Service Worker) to spin up a fully functional local API server in seconds.
The generator supports two output modes. Pretty JSON formats the output with 2-space indentation and newlines for maximum readability during development and debugging. Compact JSON removes all whitespace for minimal file size, ideal for embedding in code or config files where byte count matters.
All mock data is generated server-side based on your schema definition, but nothing is stored. Your endpoint definitions and the generated responses are processed in memory and discarded immediately. No account is required, and no data is logged or retained. It's safe to use this tool with schema definitions that describe sensitive API structures — the field names and types you define never leave the request/response cycle.