What is Mockoon used for?

Mockoon is a free, open-source desktop app and CLI for designing and running mock REST APIs locally, with an optional cloud for teams. It is a good fit for developing against APIs that are not ready yet, simulating API errors and latency in tests, and running mock APIs in CI pipelines.

Is Mockoon open source?

Yes. Mockoon is open source under the MIT licence. Its source code is on GitHub at mockoon/mockoon and is written mainly in TypeScript.

Yes. Mockoon is open source, so the software itself is free to use. A managed cloud version is also available, with paid plans from €10 per seat per month.

What is Mockoon an alternative to?

Mockoon is an open-source alternative to Beeceptor, Postman, Apifox and ReadyAPI. Other open-source alternatives to Beeceptor include Mocky.

Is Mockoon actively maintained?

Yes. The most recent commit to Mockoon was on 2 October 2026, and the latest release is v9.9.0, published on 16 September 2026. The project has 8.4k stars on GitHub.

Mockoon: open-source alternative to Beeceptor, Postman

About Mockoon

Mockoon is an open-source tool for designing and running mock APIs. It combines a desktop application for building mock servers locally with a command-line tool for running those mocks in headless environments, and it requires no remote deployment or account.

API mocking reduces dependence on external services and their limits such as rate limits, costs and availability. Mockoon lets you control routes in detail, including HTTP methods and statuses, regex paths, file serving and custom headers. It supports OpenAPI import, JSON templating, HTTPS, a proxy forwarding mode and logs of incoming and forwarded requests. Teams can simulate errors and latencies and onboard new members with a consistent test environment.

The desktop app is built with Electron and TypeScript under the MIT licence and installs through Homebrew, winget, Chocolatey, the Windows Store, Snap or AUR. The CLI is also available as a Docker image for self-hosting mock APIs, and a separate cloud offering supports team collaboration, data sync and deployment of mock APIs.

Key features

Unlimited local mock servers and routes
Control over methods, statuses and regex paths
OpenAPI compatibility
JSON templating and proxy forwarding
Request logs and HTTPS support
CLI and Docker image for CI

Good fit for

→Developing against APIs that are not ready yet
→Simulating API errors and latency in tests
→Running mock APIs in CI pipelines

Built with: TypeScript; Electron
Tags: api-mocking; mock-server; openapi; rest-api; electron; cli; developer-tools; testing

Mockoon: questions and answers

What is Mockoon used for?: Mockoon is a free, open-source desktop app and CLI for designing and running mock REST APIs locally, with an optional cloud for teams. It is a good fit for developing against APIs that are not ready yet, simulating API errors and latency in tests, and running mock APIs in CI pipelines.
Is Mockoon open source?: Yes. Mockoon is open source under the MIT licence. Its source code is on GitHub at mockoon/mockoon and is written mainly in TypeScript.
Is Mockoon free?: Yes. Mockoon is open source, so the software itself is free to use. A managed cloud version is also available, with paid plans from €10 per seat per month.
What is Mockoon an alternative to?: Mockoon is an open-source alternative to Beeceptor, Postman, Apifox and ReadyAPI. Other open-source alternatives to Beeceptor include Mocky.
Is Mockoon actively maintained?: Yes. The most recent commit to Mockoon was on 2 October 2026, and the latest release is v9.9.0, published on 16 September 2026. The project has 8.4k stars on GitHub.