Turn Your OpenAPI Spec
into a Live Mock Server – Instantly

Upload your OpenAPI YAML file and get an AI-powered mock API server
with realistic responses – no setup, no code.

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Drop In Your
OpenAPI Spec

Upload your YAML/JSON spec to generate a contract-first mock environment — aligned with your design-first workflows.

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Launch an AI-Powered
Mock Server

Bring your API specification to life with realistic, schema-compliant responses powered by AI. Use it for early integrations, stakeholders, and cool demos.

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Simulate API Behaviors
Customize, Iterate

Model edge cases, simulate failures, and remove dependencies among team — all without touching real services.

Upload OpenAPI Specification

Drag & drop your OpenAPI/Swagger file to get started

or

file.yaml

Click "Create Mock Server" button to continue.

Please select a valid file.
Processing your API specification...

Your Mock Server is Live!

http://localhost:3000

Dive in to explore the API routes, inspect live traffic, and fine-tune responses—all from one powerful dashboard. We've used AI to generate realistic mock data, so your API feels integration/demo ready from the start.

Launch Dashboard

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Benefits

Move Fast — No Backend Required

Speed through your development cycle without waiting on the backend team. As soon as you have an OpenAPI spec, you can get a working mock API. Plug it into your frontend, test flows, and ship confidently — all before the real API is even built.

Zero Code, Instant Setup

No scaffolding, no boilerplate, no SDKs to install. Just drop your YAML file and get a working API URL in seconds. Whether you're prototyping, demoing, or building automated tests — you're ready to go, instantly.

Realistic Mock Data Out of the Box

Responses aren't just 'lorem ipsum' — our AI engine understands your schema and returns data that looks and feels real. Think: believable product names, valid dates, plausible user records. It's demo-worthy from the first response.

Save on API Costs

Hitting production or 3rd-party staging environments during development can be expensive — especially when rate limits and paid API quotas get in the way. Mock servers give you unlimited, cost-free endpoints to test with.

Test for Scale and Performance

Simulate high traffic loads without touching the real API. Run integration tests, load tests, and edge-case validations — all using the mock endpoints. Perfect for performance benchmarking or CI/CD pipelines.

Customize Anything

Need the same product ID every time? Want errors on every third request? Use Beeceptor's visual rule editor to override or fine-tune any field — without writing a single line of backend logic.

Free to Start, No Strings Attached

All registered Beeceptor users can use the OpenAPI mock server — completely free. Just upload your spec (max 500KB), and you're in. Perfect for side projects, internal tools, or exploring before committing.