Do I need to write code to use Mock API Builder?

No. Define your data structure in the UI and we generate realistic mock data. You can also import OpenAPI, GraphQL SDL, .proto, or WSDL for a faster start.

Can I import my existing OpenAPI/Swagger specifications?

Yes. OpenAPI 3.x and Swagger 2.0 are supported. Import a spec and we generate endpoints with mock data. GraphQL, gRPC, and SOAP imports are available too.

Is Mock API Builder really free?

Yes. Mock API Builder is free to use with no credit card required. Fair-use rate limits and monthly usage quotas apply so the service stays reliable for everyone. Paid upgrade plans are not offered yet.

How do I share my mock API with my team?

Each mock API gets a unique shareable URL. You can keep a project public or lock it down with authentication.

Does it support authentication and custom headers?

Yes. Secure mock endpoints with API tokens, JWT, and custom headers. Account sign-in supports email/password, OAuth, and organization SSO (SAML / OIDC). CORS is enabled by default for allowed origins.

Does Mock API Builder require account registration?

No account needed to get started. Guest Mode lets you create and call mock APIs for 7 days (up to 5 projects per session). Editing endpoints, settings, analytics, and request replay require a free account.

How do I recover my account if I forget my password?

Use the "Forgot Password" link on the sign-in page. We send a reset link to your registered email so you can regain access.

Do I need to write code to use Mock API Builder?

No. Define your data structure in the UI and we generate realistic mock data. You can also import OpenAPI, GraphQL SDL, .proto, or WSDL for a faster start.

Can I import my existing OpenAPI/Swagger specifications?

Yes. OpenAPI 3.x and Swagger 2.0 are supported. Import a spec and we generate endpoints with mock data. GraphQL, gRPC, and SOAP imports are available too.

Is Mock API Builder really free?

Yes. Mock API Builder is free to use with no credit card required. Fair-use rate limits and monthly usage quotas apply so the service stays reliable for everyone. Paid upgrade plans are not offered yet.

How do I share my mock API with my team?

Each mock API gets a unique shareable URL. You can keep a project public or lock it down with authentication.

Does it support authentication and custom headers?

Yes. Secure mock endpoints with API tokens, JWT, and custom headers. Account sign-in supports email/password, OAuth, and organization SSO (SAML / OIDC). CORS is enabled by default for allowed origins.

Does Mock API Builder require account registration?

No account needed to get started. Guest Mode lets you create and call mock APIs for 7 days (up to 5 projects per session). Editing endpoints, settings, analytics, and request replay require a free account.

How do I recover my account if I forget my password?

Use the "Forgot Password" link on the sign-in page. We send a reset link to your registered email so you can regain access.

Free to use · fair-use limits

Mock REST, GraphQL, gRPC, and SOAP in one workspace

Everything you need to create, test, and share mock APIs across REST, GraphQL, gRPC, and SOAP. Instant mock data, OpenAPI import, and collaboration tools — free to start.

Free

Fair-use limits

< 30s

Typical API setup

Protocols supported

Multi

Spec import formats

Everything You Need

Import a contract, get a live URL, and share it with your team

Build & Generate

OpenAPI / Swagger Import

Import OpenAPI 3.x and Swagger 2.0 specifications. Automatically generate mock endpoints from your API contracts in seconds.

Auto-generate endpoints
Support for OpenAPI 3.x & Swagger 2.0
Preserve schema definitions

Instant Mock Generation

Create working mock APIs without coding. Define fields and data types, and we generate realistic mock data automatically. REST, GraphQL, gRPC, and SOAP are supported.

No coding required
REST, GraphQL, gRPC & SOAP
Realistic data generation

Webhook Support

Coming Soon

Outbound subscriptions and a webhook inbox for integration testing are planned for a future release.

Coming soon
Outbound event subscriptions
Inbound webhook inbox

Test & Debug

Request Logging & Analytics

View requests and responses in real time. Inspect headers and bodies, then replay or compare logged calls on account projects.

Real-time request logs
Replay & side-by-side diff
Request history

CORS & Custom Headers

CORS is enabled by default for allowed origins. Set custom response headers and status codes per endpoint.

CORS enabled by default
Custom response headers
Status code control

Rate Limiting & Quotas

Platform rate limits and monthly usage quotas help keep the service reliable for everyone.

Per-route rate limits
Monthly usage quotas
429 responses with Retry-After

Collaborate & Secure

Easy Sharing & Collaboration

Share mock APIs with teammates via a live URL when frontend work needs the contract before the backend is ready.

Generate shareable URLs
Public & private APIs
Team collaboration

Authentication Support

Secure mock endpoints with API tokens, JWT, and custom headers. Sign in with email, OAuth, or organization SSO (SAML / OIDC).

API token & JWT on mocks
Email / OAuth sign-in
Enterprise SAML / OIDC

Guest Mode

Try Mock API Builder instantly without creating an account. Guest projects last 7 days (up to 5 per session). Create and call mocks; an account unlocks editing, settings, analytics, and replay.

No account required
7-day lifespan · 5 projects/session
Save permanently with free account

Built for frontend, QA, and API design

Solo or team — get a shareable mock without waiting on the backend

Frontend Development

Build and test your frontend applications without waiting for backend APIs to be ready.

Parallel developmentInstant feedbackNo backend dependencies

API Testing

Create comprehensive test scenarios with realistic mock data and edge cases.

Edge case testingAutomated testingCI/CD integration

API Prototyping

Design and validate API contracts before investing in backend implementation.

Quick iterationStakeholder demosContract validation

Mock API Builder vs Traditional Development

See how a live mock URL shortens the wait for a real backend

Traditional Approach

Wait days for backend APIs
Manual mock data creation
Complex server setup
No collaboration tools
Expensive infrastructure
Limited testing scenarios

With Mock API Builder

Create APIs in seconds
Automatic realistic data
Zero infrastructure setup
Built-in team sharing
Free to use with fair-use limits
Comprehensive test coverage

Frequently Asked Questions

Get answers to common questions about Mock API Builder

Ready to Build Your First Mock API?

Create your first mock endpoint in under 30 seconds.

No credit card required · Setup in under 2 minutes · Fair-use limits