Realistic Mock APIs
From OpenAPI/Swagger Spec

Get an AI powered mock server with
beautiful, lifelike responses, in a few seconds.

Powered by 300+ data generators to craft smart, lifelike responses.

See how the OpenAPI AI Mock works

Try Now
Try this OpenAPI specification
GET
openapi: 3.0.0
info:
  title: Users API
  version: 1.0.0
paths:
  /v1/user:
    get:
      responses:
        '200':
          description: A user object
          content:
            application/json:
              schema:
                type: object
                properties:
                  id:
                    type: string
                  username:
                    type: string
                  email:
                    type: string
                  country:
                    type: string
                  address:
                    type: object
                    properties:
                      street:
                        type: string
                      city:
                        type: string
                      state:
                        type: string
                      zip:
                        type: string
tick

Upload Your Spec

Drop in your OpenAPI YAML/JSON to spin up a contract-first mock environment.

tick

Start Your Mock Server

Turn your API design into an AI-powered server with realistic, schema-aware responses.

tick

Simulate & Iterate

Model edge cases, test failures, and decouple teams - all without real services.

Your OpenAPI spec deserves
more than a static file!

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, please wait...

Your Mock Server is Live!

http://localhost:3000

The mock server is ready with AI-generated, realistic data.
Explore API routes, monitor live traffic, and build overrides using mock rules from the dashboard page.

Launch Dashboard

Error

An error occurred while processing your request.

The Smarter Way to Mock APIs

Got an OpenAPI spec? You’re already ahead.

Beeceptor uses AI-powered smart-contracts to instantly turn your OpenAPI spec into a live, integration-ready mock server, complete with realistic, golden test data. It’s not just mock responses, it’s production-grade simulation, built to unblock teams and accelerate development from day one.

Virtualize Any Third-Party API

No sandbox? No problem. Easily virtualize vendor APIs and test against stable, predictable responses across all your dev, QA, and staging environments.

Better API Design from Day One

Contract-first development encourages thoughtful endpoint & data-model design before coding begins. You get cleaner, intuitive APIs for long-term success.

Move Fast — No Backend Needed

Skip the backend wait. Upload your OpenAPI spec and instantly get a working mock API. Connect it to your frontend, test flows, and ship faster.

No Code, Instant Setup

Drop in your YAML file and you're live - no SDKs, no boilerplate. Perfect for prototypes, demos, or automated tests with zero setup hassle.

AI-Generated, Realistic Test Data

Beeceptor uses AI to generate golden test data for every entity and field in your OpenAPI spec. Just like production — no code required.

Start Free

Use the OpenAPI mock server at no cost. Just upload your spec (up to 500KB) and get a live endpoint. Use this for testing, demos, and sharing with dependent teams.

Cut API Usage Costs

Avoid burning API quotas in dev or staging. Use mock endpoints to test freely — without worrying about rate limits or 3rd-party billing.

Test for Scale and Speed

Run load tests, simulate traffic spikes, or test edge cases — all without touching the real backend. Ideal for CI/CD and performance testing.

Control Every Response

Set fixed values, trigger errors, or add logic — all using Beeceptor's rule editor. Customize mock behavior without backend code.