Build, test, and share realistic mock APIs in minutes — REST, GraphQL, gRPC, and SOAP, no backend required
Mock API Builder is a powerful tool that lets you create fully functional mock APIs — REST, GraphQL, gRPC, and SOAP — without writing any backend code. Perfect for frontend developers, testers, and teams who need to prototype, test, or demonstrate API integrations quickly. Each project uses one protocol; see Choosing a Protocol for how that works.
Whether you're building a React app, testing an iOS application, or demonstrating a new feature to stakeholders, Mock API Builder provides instant, realistic API responses without the wait.
Start frontend development immediately without waiting for backend APIs to be built.
Create specific test scenarios and edge cases that would be difficult to reproduce in production.
Share mock APIs with team members, stakeholders, or clients for demos and feedback.
No servers to configure, no databases to set up—just instant, working APIs.
Try the platform instantly without creating an account — build for 7 days
Mock REST, GraphQL, gRPC, and SOAP — one protocol per project, with protocol-aware testers and call URLs
REST projects support all HTTP methods with proper status codes and responses
Powered by Faker.js with 100+ data generators
Import OpenAPI, GraphQL SDL, .proto, or WSDL to create complete APIs instantly
Start with pre-built templates for common use cases
Follow our Quick Start Guide and create your first mock API in just 5 minutes — or pick a protocol first.
