# Free Mock REST & LLM API for Testing & Development

MockAPI Dog is a free, no-signup-required tool that lets you create and deploy mock REST APIs and LLM streaming endpoints instantly. Perfect for developers building applications that need quick API prototyping and AI integration testing.

## How it works

### Generate your endpoint

A unique short code is automatically generated for you

### Configure your response

Select REST API with JSON or LLM streaming with AI-like responses

### Deploy & use

Click save and your mock API is live immediately. Copy the URL and use it anywhere

## Why use MockAPI Dog?

### Instant setup

No registration, no API keys, no configuration files. Just open the page and start creating mock endpoints in seconds.

### REST & LLM mocking

Create traditional REST APIs with JSON responses or mock LLM streaming endpoints compatible with OpenAI, Anthropic, and other providers.

### Advanced testing

Simulate network delays, random failures, conditional errors, and LLM streaming behavior. Test how your app handles all conditions.

### 100% free

Completely free to use. No limits, no premium tiers, no credit card required.

## Perfect for

- **Frontend development:** Build and test your UI without waiting for backend APIs
- **AI/LLM integration:** Test ChatGPT, Claude, or custom LLM integrations without burning through API credits
- **API testing:** Simulate different responses and error scenarios
- **Rapid prototyping:** Quickly validate ideas and demonstrate concepts
- **Learning & education:** Practice API integration without complex setup
- **CI/CD testing:** Use stable mock endpoints in your automated tests

## Features

### No signup required

No authentication or signup required - start building immediately

### All HTTP methods

Support for all standard HTTP methods (GET, POST, PUT, DELETE, PATCH, HEAD, OPTIONS)

### LLM streaming support

Mock OpenAI, Anthropic, and generic streaming formats with customizable token generation

### Custom status codes

Custom HTTP status codes (200, 201, 400, 404, 500, and more)

### JSON editor

Built-in JSON editor with syntax highlighting and validation

### Delay simulation

Artificial delay simulation (test slow network conditions)

### Error testing

Random error rate testing and conditional errors based on request headers

### CORS enabled

CORS enabled for cross-origin requests from any domain

## Common use cases

### Testing AI chatbot integration

Build and test your AI chatbot UI with mock LLM responses before connecting to expensive production APIs. Save money during development.

### Testing error handling

Create endpoints that return 404, 500, or other error status codes to test how your application handles failures.

### Building without backend

Focus on frontend development while the backend is still being built. Replace mock endpoints with real ones later.

### Workshop & training

Provide students with consistent, reliable API endpoints for learning exercises without infrastructure overhead.

## Frequently Asked Questions

### Do I need to create an account?

No! MockAPI Dog requires no signup or authentication. Just visit the site and start creating mock endpoints immediately.

### Is it really free?

Yes, completely free with no hidden costs, premium tiers, or usage limits. We believe developers should have access to quality tools without barriers.

### Can I use this for production?

MockAPI Dog is designed for development, testing, and prototyping. While endpoints are reliable, we recommend using production-grade APIs for live applications.

### What LLM providers are supported?

We support OpenAI format (ChatGPT, GPT-4), Anthropic format (Claude), and generic streaming formats. The mock responses mimic the streaming behavior of these providers.

### How long do endpoints stay active?

Endpoints remain active as long as they're being used. Inactive endpoints may be cleaned up periodically to maintain service quality.

## Start building now

MockAPI Dog makes API development faster and easier. Whether you're building a prototype, testing edge cases, integrating AI features, or learning web development, get started in seconds with no barriers.

**No installation. No configuration. No signup. Just code.**