A toolkit with common assertions and mocks that plays nicely with the standard library

Industry standard API mocking for JavaScript.

Most popular Mocking framework for unit tests written in Java

Mockery is a simple yet flexible PHP mock object framework for use in unit testing with PHPUnit, PHPSpec or any other testing framework. Its core goal is to offer a test double framework with a succinct API capable of clearly defining all possible object operations and interactions using a human readable Domain Specific Language (DSL).

Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source.

A tool for mocking HTTP services

A mock code autogenerator for Go

Stub your network requests easily! Test your apps with fake network data and custom response time, response code and headers!

Turn any OpenAPI2/3 and Postman Collection file into an API server with mocking, transformations and validations.

PowerMock is a Java framework that allows you to unit test code normally regarded as untestable.

Axios adapter that allows to easily mock requests

Pester is the ubiquitous test and mock framework for PowerShell.

Automatically mock your HTTP interactions to simplify and speed up testing

A friendly substitute for .NET mocking libraries.

Lightweight service virtualization/ API simulation / API mocking tool for developers and testers

Intercept HTTP requests at the Python socket level. Fakes the whole socket module

HTTP traffic mocking and testing made easy in Go ༼ʘ̚ل͜ʘ̚༽

Insomnia Mockbin is the underlying backend for the API mocks capability of Insomnia. It is built and used by Kong, the author of the open-source Kong Gateway.

Over the wire test doubles

Interface mocking tool for go generate