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Best API Mocking Tools in 2026

Building against an API before a live service is ready can call for tools that return controllable mock responses. Compare supported protocols and request matching, then consider dynamic responses, OpenAPI import, and mock data generation. Local deployment, free-plan availability, and paid-from pricing add practical setup and cost points. Microcks, Mockzilla, and MockServer are among the entries to compare; WireMock, Mockfly, and Knockout API are also shown. The listed criteria can help you weigh how each tool describes creating mocks and fitting them into your development workflow.

26 apps
Research read 23 Sept 2026
How the order is worked out

1

Mockzilla

Free plan Open source APILinuxMac+3

Mockzilla offers both hosted mock APIs and an offline CLI, with request validation, fault simulation, and pull-request environments.

8.8 Free plan · paid from $10/mo Visit site
2

Beeceptor

Free plan APILinuxMac+3

Beeceptor combines configurable mocks with proxying, traffic recording, and failure simulation across a wide range of API protocols.

7.7 Free plan · paid from $10/mo · 10-day trial Visit site
3

Microcks

Free plan APIExtensionLinux+4

Microcks combines API mocking, contract testing, and pipeline automation in an open-source tool.

7.5 Free plan Visit site
4

Mockfly

Free plan APIExtensionLinux+2

Mockfly combines hosted and local mock API workflows with imports, conditional responses, and team tools.

7.4 Free plan · paid from €15/mo Visit site
5

Imposter

Free plan LinuxMacSelf-hosted+1

Choose Imposter if your development or QA workflow needs configurable API mocks, request validation, data capture, or endpoint proxying.

7.3 Open source Visit site
6

json-server

Free plan APISelf-hosted

Choose json-server for a free local REST API built from JSON or JSON5 files, with routes and query features for testing and prototyping.

7.3 Open source Visit site
7

Mockoon

Free plan APILinuxMac+3

Mockoon covers local mock creation as well as automated, serverless, and private deployment workflows.

7.3 Free plan · paid from $100/mo (annual) Visit site
8

MockServer

Free plan APILinuxMac+3

MockServer covers mocking, proxying, verification, and chaos testing across a broad set of protocols and deployment options.

7.3 Free plan Visit site
9

Knockout API

Free plan APIWeb

Knockout API combines a broad set of image tools with asynchronous video background removal and developer clients.

7.2 Free plan · paid from $0.02 Visit site
10

Mocki

Free plan APISelf-hostedWeb

Mocki combines configurable API behavior, local execution, and managed hosting for development and testing.

7.2 From $15/mo · 7-day trial Visit site
11

Mockttp

Free plan LinuxMacSelf-hosted+2

Mockttp offers HTTP mocking and proxy capabilities as a JavaScript library, with support for parallel testing.

7.2 Open source Visit site
12

MockAPI

Free plan APIWeb

MockAPI provides configurable REST resources and generated data for prototyping, testing and learning.

7.1 Free plan Visit site
13

WireMock

Free plan APILinuxSelf-hosted+1

WireMock offers request matching, response simulation, and replay for testing against simulated dependencies.

6.9 Free plan Visit site
14

WireMock

Free plan APILinuxMac+3

WireMock Cloud supports a broad set of protocols and workflows, with local and CI/CD simulation options. Check the Free plan's call cap and the Enterprise quote-based pricing against your needs.

6.9 Free plan Visit site
15

moqapi.dev

Free plan APIWeb

moqapi.dev brings specification imports, endpoint generation, testing tools, and authentication testing into one platform. The Free Mode plan includes three projects, while Team costs $29 a month.

6.8 Free plan · paid from $29/mo Visit site
16

Stoplight Prism

Free plan APISelf-hostedWeb

Choose Prism if you need a free, open-source server for mocking APIs, validating data, or checking a target API against its OpenAPI document.

6.8 Free plan Visit site
17

Mirage JS

Free plan Web

Mirage JS offers a configurable way to simulate API behavior in browser-based development and testing. Its Node runtime boundary matters for teams that need to mock server-side requests.

6.7 Open source Visit site
18

Mock Service Worker

Free plan Self-hostedWeb

MSW offers reusable request mocking across browser and Node.js contexts, with support for several API protocols and clients.

6.7 Free plan Visit site
19

MockWebServer

Free plan Android

MockWebServer offers request capture and controllable responses for basic client tests.

6.7 Open source Visit site
20

OpenAPI Mock

Free plan LinuxSelf-hostedWindows

OpenAPI Mock offers flexible response generation and deployment options for OpenAPI 3.x.

6.6 Open source Visit site
21

Hoverfly

Free trial APILinuxMac+3

Choose Hoverfly Cloud if your team needs hosted API simulation for development, functional testing, or performance testing, with traffic replay and configurable simulated behavior.

6.5 From $10/mo · 14-day trial Visit site
22

OpenAPI Server

Free plan APISelf-hosted

OpenAPI Server covers local mocking, specification validation, and optional backend proxying. Its runtime requirement and lack of TypeScript mock support are important considerations.

6.5 Open source Visit site
23

Pretender.js

Free plan Web

Pretender.js provides flexible browser request mocking with route tracking and timing controls. Its browser-only scope makes it unsuitable for use outside the browser.

6.2 Open source Visit site
24

Parasoft Virtualize

Free plan LinuxMacWeb+1

6.1 Free plan Visit site
25

API-Mocked

Paid Self-hosted

API-Mocked provides a compact, self-hosted way to simulate APIs across common protocols.

5.4 Open source Visit site

#1Places #1, #2, #3, #4, #5 on this list can be bought by the makers of the software on it. See the price

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