Top 9 API Client Tools to Boost Your API Debugging Efficiency in 2025

Writing code is inherently challenging, but debugging APIs often proves even more complex. Despite advances in AI-powered coding assistants, issues like “hallucinations” in AI-generated code continue to make debugging a time-consuming and frustrating process.

Fortunately, just as Integrated Development Environments (IDEs) have accelerated coding productivity, there are several powerful API client tools designed to make API testing and debugging more efficient and manageable.

Below is a curated list of the top 9 API client tools in 2025 that can help you debug APIs faster and more effectively. Most of these tools are free or open-source, offering comprehensive features that meet the needs of both individual developers and teams.

1. EchoAPI — Advanced API Debugging for Teams

EchoAPI stands out as a modern API client designed to enhance team collaboration and developer productivity. With its intuitive interface, it streamlines API debugging, documentation generation, and real-time teamwork. Key features include an AI-powered assistant that automates testing workflows, support for private deployments to meet strict data security requirements, multi-language compatibility for seamless integration across various tech stacks, and built-in collaboration tools that make working with teams fast and efficient.

Website: echoapi.com

2. Bruno

Bruno introduces an innovative “files as projects” approach, storing API requests locally as YAML files. This design enables offline access, seamless Git integration, and enhanced privacy with no cloud dependency. Bruno is particularly suited for developers who prioritize version control and data security.

Website: usebruno.com

3. Postman

Postman remains the industry standard for API clients. It offers a comprehensive suite of features spanning the entire API lifecycle—from constructing requests and generating documentation to mocking, automated testing, and environment management. While it can be resource-intensive, its robust capabilities make it indispensable for both solo developers and large teams.

Website: postman.com

4. Insomnia

Insomnia is an open-source API client with a clean, minimalist interface and efficient performance. It supports REST, GraphQL, gRPC, and other protocols, with advanced features like test scripting and plugin extensibility. Its lightweight design makes it ideal for developers seeking an unobtrusive yet powerful tool.

Website: insomnia.rest

5. Paw

Paw is a macOS-exclusive API client known for its polished user interface and comprehensive feature set. It excels in request building, response analysis, environment management, and team collaboration. Paw also generates ready-to-use code snippets in multiple programming languages, facilitating seamless integration into development workflows.

Website: paw.cloud

6. Hoppscotch

Hoppscotch is a browser-based, open-source API client offering a lightweight and fast alternative to desktop applications. Supporting REST, GraphQL, WebSocket, and Socket.IO, it provides a streamlined interface with zero installation overhead, making it a convenient option for quick testing.

Website: hoppscotch.io

7. Thunder Client

Thunder Client is a lightweight API testing extension integrated directly into Visual Studio Code. It supports REST APIs, environment variables, request history, and import/export functionality, offering a convenient solution for developers who prefer to remain within their coding environment.

Website: thunderclient.com

8. Advanced REST Client (ARC)

ARC is a mature, no-frills API client that originated as a Chrome extension and now exists as a standalone desktop app. It supports OAuth 2.0, header management, request history, and customizable themes. While its interface is functional rather than flashy, it remains a reliable tool for API testing.

Website: advancedrestclient.com

9. HTTPie

HTTPie is a command-line API client designed to make HTTP requests intuitive and readable. Available in desktop and web versions, it supports REST, GraphQL, multi-environment management, and team collaboration without unnecessary complexity.

Website: httpie.io

Conclusion

Each of these API clients offers unique strengths tailored to different workflows and preferences. For teams aiming to accelerate API debugging with AI-driven automation, collaborative features, and strong privacy controls, EchoAPI provides a compelling, modern solution.

Explore these tools and transform your API debugging process into a more efficient and productive experience.