Postman has become a staple in API development, but it’s far from the only option. As the API ecosystem expands, developers are increasingly turning to open-source, privacy-friendly, offline-capable, and specialized tools that align better with their workflow. Whether you're a frontend developer testing REST endpoints, a backend engineer working with gRPC, or a DevOps professional automating tests, there's an API client designed for your needs.
In this list, we highlight 20 outstanding API clients and tools across web-based, desktop, IDE, CLI, and automation categories—all excellent Postman alternatives in 2025.
Top 20 Awesome API Clients
1. Apidog
Apidog is a unified platform for API design, documentation, testing, and mocking, offering robust features with a generous free tier—ideal for teams looking to streamline their entire API development workflow.
Key Features:
- Combines Postman + Swagger + Mock server capabilities.
- Role-based collaboration for teams.
- Designed for fintech, SaaS, and enterprise teams.
- Web and desktop versions available.
2. Restfox
Restfox is an offline-first web-based HTTP client with a design inspired by Firefox DevTools. It’s minimal and designed for speed and privacy.
Key Features:
- Works completely offline.
- Tabbed interface with request history and saved endpoints.
- Lightweight and blazing fast.
- Ideal for local testing and debugging.
3. Firecamp
Firecamp offers an all-in-one collaborative API development environment accessible via the web. It aims to streamline real-time API testing.
Key Features:
- REST, GraphQL, WebSocket, and gRPC support.
- Multiple client views including code and visual formats.
- VS Code-like UI for an intuitive experience.
- Workspace collaboration features.
4. gRPC UI
gRPC UI provides a graphical interface to interact with gRPC endpoints directly in the browser. It helps visualize, explore, and test your service APIs.
Key Features:
- Dynamic service discovery via proto files.
- Real-time interaction with gRPC methods.
- Ideal for backend developers using gRPC in microservices.
5. Prestige
Prestige is a text-based, in-browser API client that works like Markdown for HTTP requests. It’s ideal for developers who prefer working in plain text.
Key Features:
- Send requests using minimal syntax.
- Fully offline and open-source.
- Syntax highlighting and collapsible request/response panels.
6. Yaade – Web Edition
Yaade (Yet Another API Development Environment) is a self-hosted, open-source API client built for teams who value data privacy and security.
Key Features:
- Encrypted and persistent storage for requests.
- Multi-user support with authentication.
- Ideal for on-premises environments and teams.
7. Requestly
Requestly is a versatile browser extension and web client used to intercept, mock, and debug APIs in real-time—perfect for frontend developers.
Key Features:
- API mocking, redirection, and modification.
- Browser extension and web interface.
- Supports custom rules for debugging and testing.
8. Hoppscotch
Hoppscotch is a modern, sleek, and fast browser-based API client designed for speed and simplicity. Originally inspired by Postman, it's now a full ecosystem supporting REST, GraphQL, WebSocket, and more.
Key Features:
- No installation required — runs in your browser.
- Support for REST, GraphQL, WebSockets, SSE, and MQTT.
- Workspaces, collections, and environment variables.
- Open-source and actively maintained.
9. Bruno
Bruno is an open-source, offline-first API client that uses plain-text files (YAML/JSON) to define and organize requests—perfect for version control.
Key Features:
- File-based configuration compatible with Git.
- Supports REST, GraphQL, and gRPC (in progress).
- Lightweight, local-first design.
- Scriptable with JavaScript snippets.
10. Yaak
Yaak is a beautifully designed native API client for developers who want a fast and intuitive experience on the desktop.
Key Features:
- Built-in support for REST APIs.
- Tab-based navigation and response rendering.
- User-friendly layout and minimal setup.
11. API Dash
API Dash is a cross-platform open-source API client with a clean and structured interface. It’s particularly appealing for those who want a modern alternative to Insomnia.
Key Features:
- REST API testing with request history and saved collections.
- Polished UI with tabs and environment variables.
- Available for Windows, macOS, and Linux.
12. ezy
ezy is a graphical gRPC and gRPC-Web client that focuses on ease of use and protocol-specific testing.
Key Features:
- Send and inspect gRPC/gRPC-Web calls.
- GUI interface for Protobuf and message management.
- Ideal for gRPC-heavy stacks.
13. BloomRPC
BloomRPC was one of the first GUI tools for working with gRPC services. It’s unmaintained but still useful for legacy workflows.
Key Features:
- Proto file management.
- Real-time request/response viewing.
- Simple and direct interface for gRPC calls.
14. Milkman
Milkman is an extensible API workbench that supports plugins to adapt to different protocols and workflows.
Key Features:
- REST, GraphQL, SOAP, and more via plugins.
- Workspace-based structure.
- Export and import environments and requests.
15. Insomnium
Insomnium is a local-first fork of Insomnia with a strong focus on privacy and offline functionality.
Key Features:
- 100% local storage with no cloud sync.
- Full Insomnia feature set with extended offline support.
- Great for security-conscious developers.
16. Pororoca
Pororoca is a network debugging tool focused on HTTP/2 and HTTP/3 support, making it ideal for developers exploring newer web protocols.
Key Features:
- Inspect and test HTTP/1.1, HTTP/2, and HTTP/3.
- Modern interface for deep packet inspection.
- Lightweight and fast.
17. Nightingale REST Client
Nightingale is a native Windows application offering a modern take on REST clients with minimal resource usage.
Key Features:
- Windows-specific optimization.
- Tabbed interface and environment management.
- REST API testing with saved sessions.
- Deploy mock servers
18.ATAC
ATAC is a lightweight, terminal-based API client that brings Postman-like capabilities to the command line. Designed for simplicity and speed, it’s great for developers who live in the terminal but want a structured, menu-driven way to send and inspect HTTP requests.
Key Features:
- TUI (Text User Interface) with form-based inputs.
- Supports common HTTP verbs and custom headers.
- Clean history and request management.
- Built for productivity inside terminal workflows.
- Cross-platform support (Linux, macOS, Windows with WSL).
19. Cartero
Cartero is a simple, native HTTP client focused on performance and minimalism.
Key Features:
- Multi-platform support.
- Direct HTTP inspection and editing.
- Ideal for quick, repeated API testing.
20. VS Code REST Client
This plugin for Visual Studio Code allows developers to send HTTP requests directly from .http or .rest files inside the editor.
Key Features:
- No need to leave your code editor.
- Syntax highlighting and environment support.
- View responses inline with source code.
CLI-Based Clients and API Testing Tools
In addition to graphical tools, command-line and test automation tools are essential for continuous integration, performance testing, and scripting.
CLI Clients:
- curl – The original HTTP command-line tool.
- HTTPie – Human-readable output and syntax.
- grpcurl – cURL for gRPC endpoints.
- xh, curlie – Friendly and fast request runners.
- HttpRepl, posting, ain, evans, httpYac, ATAC – Tools for various HTTP/gRPC CLI workflows.
Automated Testing & Load Testing:
-
Hurl – Define and run HTTP tests via
.hurlfiles. - Karate – Full-featured framework for testing APIs.
- Tavern, Venom, pyresttest – Great for CI flows.
- runn, scenarigo, Schemathesis, Dredd, abao, HttpRunner – Cover contract testing, scenario testing, and OpenAPI validation.
- k6, Artillery – High-performance tools for load testing at scale.
Final Thoughts
With Postman no longer the only player in town, 2025 offers a rich ecosystem of API development tools. From sleek web-based alternatives like Hoppscotch to CLI-first utilities like HTTPie and all-in-one platforms like Apidog, developers now have the flexibility to pick the tool that fits their exact needs—whether that’s open-source, offline capability, or support for gRPC and WebSockets.
Explore, contribute, and customize your API workflow with any of these tools—and supercharge your productivity in the process.
Top comments (11)
What about VSCode extensions, any good suggestion?
Great question! For VS Code, I recommend the REST Client extension — it lets you send HTTP requests directly from .http files, making testing APIs super easy without leaving the editor. It’s lightweight and very popular among devs.
There are also some others like Thunder Client if you want a more Postman-like experience inside VS Code.
Thunder Client is a good client.
As Emmanuel said, it's similar to Postman, but with fewer features.
Good list!
Thank you samma glad it helps.
Bruno is my favourite, but thanks OP for the list!
Awesome!!! You are welcome
Ouch! You did a whole 20 and missed voiden.md
Thanks for the insights into some of these!
Most do look like a different theme of the same tool, but I assume the paywalling is different.
For the most it's well known where they differ, some are a tad less popular so I'll look more into them :)
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Interesting: didn't know these existed. Actually I really like the integrated
/docsendpoint inside FastAPI because it's highly coupled with the code.Missed Posting.sh too, slick UI, capable of full keyboard control, and the API collections are all yaml so easy for git control.
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