1.mswjs / msw
The industry standard for API mocking in JavaScript.
+525 stars
from 17,801 · score 6.27
Trending repositories
Ranked by Attention Score: stars gained over the last 180 complete days
28 repositories by Attention Score · May 7, 2026 – Nov 2, 2026 (UTC)
2.stretchr / testify
A toolkit with common assertions and mocks that plays nicely with the standard library
+435 stars
from 25,805 · score 6.08
3.mockoon / mockoon
Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source.
+269 stars
from 8,198 · score 5.60
4.godot-gdunit-labs / gdUnit4
Embedded unit testing framework for Godot 4 supporting GDScript and C#. Features test-driven development, embedded test inspector, extensive assertions, mocking, scene testing.
+249 stars
from 1,037 · score 5.52
5.wiremock / wiremock
A tool for mocking HTTP services
+218 stars
from 7,197 · score 5.39
6.microcks / microcks
The open source, cloud native tool for API Mocking and Testing. Microcks is a Cloud Native Computing Foundation incubating project 🚀
+203 stars
from 1,870 · score 5.32
7.stoplightio / prism
Turn any OpenAPI2/3 and Postman Collection file into an API server with mocking, transformations and validations.
+164 stars
from 4,900 · score 5.11
8.vektra / mockery
A mock code autogenerator for Go
+118 stars
from 7,057 · score 4.78
9.pester / Pester
Pester is the ubiquitous test and mock framework for PowerShell.
+113 stars
from 3,259 · score 4.74
10.mockito / mockito
Most popular Mocking framework for unit tests written in Java
+111 stars
from 15,341 · score 4.72
11.kevin1024 / vcrpy
Automatically mock your HTTP interactions to simplify and speed up testing
+69 stars
from 2,953 · score 4.25
12.SpectoLabs / hoverfly
Lightweight service virtualization/ API simulation / API mocking tool for developers and testers
+58 stars
from 2,475 · score 4.08
13.nsubstitute / NSubstitute
A friendly substitute for .NET mocking libraries.
+47 stars
from 2,936 · score 3.87
14.FakeItEasy / FakeItEasy
The easy mocking library for .NET
+34 stars
from 1,821 · score 3.56
15.mockery / mockery
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).
+27 stars
from 10,698 · score 3.33
16.matryer / moq
Interface mocking tool for go generate
+22 stars
from 2,184 · score 3.14
17.AliSoftware / OHHTTPStubs
Stub your network requests easily! Test your apps with fake network data and custom response time, response code and headers!
+14 stars
from 5,052 · score 2.71
18.richardszalay / mockhttp
Testing layer for Microsoft's HttpClient library. Create canned responses using a fluent API.
+13 stars
from 1,751 · score 2.64
19.3lvis / Networking
Swift HTTP Networking with stubbing and caching support
+9 stars
from 1,372 · score 2.30
20.zuplo / mockbin
Mockbin by Zuplo. Mock, Test, and View HTTP Requests and Responses
+9 stars
from 134 · score 2.30
21.Brightify / Cuckoo
Boilerplate-free mocking framework for Swift!
+8 stars
from 1,736 · score 2.20
22.tianchangNorth / pocket-mocker
In-page HTTP controller for frontend development. Intercept, modify, and simulate API responses directly in the browser.
+8 stars
from 517 · score 2.20
23.powermock / powermock
PowerMock is a Java framework that allows you to unit test code normally regarded as untestable.
+6 stars
from 4,159 · score 1.95
24.natenho / Mockaco
🐵 HTTP mock server, useful to stub services and simulate dynamic API responses, leveraging ASP.NET Core features, built-in fake data generation and pure C# scripting
+4 stars
from 347 · score 1.61
25.Ortus-Solutions / TestBox
TestBox is a cutting-edge testing and mocking framework for the BoxLang JVM language and ColdFusion (CFML), built on Behavior-Driven Development (BDD) to offer a clear and intuitive syntax for writing tests.
+3 stars
from 70 · score 1.39
26.SpectoLabs / hoverfly-java
Java binding for Hoverfly
+2 stars
from 175 · score 1.10
27.iridakos / duckrailsArchived
Development tool to mock API endpoints quickly and easily - NOT MAINTAINED
+1 stars
from 1,707 · score 0.69
28.balinomad / go-mockfs
Feature-rich filesystem mocking for Go tests: comprehensive error injection, latency simulation, write operations, operation statistics, and standalone file handles. Built on testing/fstest.MapFS with comprehensive fs.FS interface support.
+1 stars
from 8 · score 0.69