Testing APIs: Comparison of WireMock, Spotlight Prism, Mountebank, MockServer, and Broadcom DevTest

Published by: Audrey Puckett

5 min read

APIs, or Application Programming Interfaces, are sets of rules and protocols that allow different software applications to communicate with each other. They define how requests and responses should be structured, enabling different systems, services, or components to interact seamlessly. APIs can be used for a wide variety of purposes, such as retrieving data, performing operations, or integrating different software systems. APIs are the backbone of modern software architecture, allowing developers to build complex applications by leveraging existing services and data. For example, when you use a mobile app to check the weather, the app communicates with a weather API to retrieve the latest weather data.

API testing is crucial because APIs are often the primary means through which different software components communicate. Testing APIs ensures that these interactions are reliable, secure, and perform as expected. Additionally, mocking APIs during testing allows developers to simulate different scenarios and behaviors without depending on the availability or reliability of external services, making the development and testing process more efficient and controlled.

Executive Summary

In this article, we compare five popular API testing technologies including WireMock, Spotlight Prism, Mountebank, MockServer, and Broadcom DevTest. This article serves to highlight the strengths of each technology and provide recommendations for the best use case. The below table highlights some pertinent differences.

WireMock

WireMock is one of the most popular mocking tools, especially in the Java ecosystem. It’s known for its ease of use, with a simple API and a wide range of features, including support for stubbing, recording, and playback. WireMock is particularly strong in scenarios where you need to simulate complex API interactions. WireMock is great for beginners as it is known for its simplicity and ease of use earning it a beginner rating for experience level.

Strengths:

• Easy to use, especially for Java developers.
• Supports recording and playback of HTTP interactions.
• Strong community support and documentation.

Its ability to connect seamlessly with Java applications and CI/CD pipelines makes it excellent for automated testing environments. — Dhanik Sahni

Spotlight Prism

Prism by Stoplight is focused on mocking OpenAPI (Swagger) specifications. It’s ideal for teams that follow a contract-first approach to API development. Prism can validate requests and responses against an API spec, ensuring that mocks are always compliant with the defined contract. Due to its high compatibility with OpenAPI, it earns a beginner experience level rating.

Strengths:

• Excellent for contract-first API development.
• Offers strong validation against API specifications.
• Can run mocks based on real-time traffic and data.

Customer reviews rate Spotlight at 4.4 out of 5 stars and consistently highlight the resource’s ease of use and clear documentation — Reviewers

Mountebank

Mountebank is a versatile, protocol-agnostic tool that can mock HTTP, HTTPS, TCP, and more. It’s a great choice for teams that need to simulate a wide range of services, not just HTTP APIs. Mountebank is also notable for its support for injecting faults and simulating performance issues, making it ideal for testing under failure conditions. Beginners might find the setup and configuration a bit more challenging, especially if they are not familiar with the different protocols Mountebank can mock. The documentation is helpful, but the learning curve is steeper compared to more specialized tools like WireMock or Prism earning it an experience level of moderate.

Strengths:

• Protocol-agnostic.
• Can simulate various types of services.
• Supports fault injection and latency simulation.

It stands out from the crowd because it’s non-modal and multi-protocol. The tool offers service virtualization for free without any platform constraints. — Katie Sanders

MockServer

MockServer is a powerful and flexible tool with a strong emphasis on being language-agnostic or not tied to any specific programming language. It supports a wide range of features, including HTTP and HTTPS mocking, verification, and expectation matching. The ability to define mocks through code or JSON allows for great flexibility, making it a favorite for developers who want to maintain mocks as part of their version-controlled codebase. The technology is rated as moderate experience level due to it having a more complex setup process.

Strengths:

• Highly configurable.
• Strong verification features.
• Easily integrates with CI/CD pipelines.

MockServer can be used to effectively isolate client-side interactions for testing, with minimal dependency on actual server availability. — Kasper Sig

Broadcom DevTest

Broadcom DevTest is an enterprise-grade service virtualization solution that goes beyond simple mocking. It’s designed for large organizations that need to simulate complex, multi-layered services and systems. DevTest offers a comprehensive suite of tools for testing, including performance testing and service virtualization at scale. It’s overkill for most beginners and has a significant learning curve. The setup is complex, and the tool is designed for advanced users who need to virtualize services in a large enterprise environment.

Strengths:

• Enterprise-grade with extensive features.
• Scales well for large, complex environments.
• Strong support and integrations for enterprise systems.

Based on customer reviews, 92% of users would be willing to recommend the technology to others. Reviewers highlight the positives of the technology such as removing barriers to testing— Reviewers

Which is best for you?

The “best” tool depends heavily on your specific needs:

• For simplicity and ease of use, especially in a Java-centric environment, WireMock is an excellent choice.
• For API contract testing where OpenAPI/Swagger is the standard, Prism shines.
• For protocol-agnostic and advanced testing scenarios, especially in diverse environments, Mountebank offers unmatched flexibility.
• For large-scale enterprise environments with a need for sophisticated service virtualization, Broadcom DevTest is unparalleled.
• For highly configurable and code-driven mocks, MockServer stands out, especially for teams looking for deep integration with CI/CD pipelines.

In summary, WireMock is likely the best fit for most general-purpose HTTP mocking needs, thanks to its balance of power and simplicity. However, for specialized requirements, other tools like Prism or Mountebank may be better suited. Broadcom DevTest is the go-to for large enterprises, while MockServer appeals to developers who prioritize flexibility and control.

We hope this article helps you discover the best API testing technology for your needs. At Strategio, we’re committed to making a positive impact through diversity and knowledge sharing. Just as we approach our research with thoroughness and care, we also prepare our technologists for our clients’ unique roles by fostering a growth mindset and a commitment to continuous improvement #BeBetter. To learn more about how we can support your goals, visit our website and connect with our team.