5 Free API Testing Tools for WebSocket

In the world of API testing, WebSocket technology plays a crucial role in enabling real-time, full-duplex communication between clients and servers. WebSocket is commonly used in applications that require continuous data exchange, such as chat applications, online gaming, financial trading platforms, and real-time notifications.

While Postman is a well-known tool for testing APIs, many developers are searching for alternatives when it comes to testing WebSocket connections. Postman is excellent for traditional HTTP-based testing but lacks some of the essential features for WebSocket testing. In this blog, we will explore some free tools to test WebSockets that are not Postman, highlighting their key features and benefits.

1. Apidog — A Comprehensive WebSocket Testing Tool

Apidog is an all-in-one API development tool that offers comprehensive WebSocket testing capabilities, allowing you to test WebSocket APIs with ease. Unlike Postman, Apidog is designed with full support for both HTTP and WebSocket API management.

Key Features in terms of WebSocket testing:

• Create WebSocket Endpoints: You can easily create WebSocket endpoints by specifying the ws:// or wss:// server URL and establishing a connection.
• Message Formatting: Supports multiple message formats including Text, JSON, XML, HTML, and Binary formats (Base64 and Hexadecimal). This flexibility helps you test various types of WebSocket messages.
• Real-time Monitoring: Apidog allows you to view both sent and received WebSocket messages in real-time, helping you track the connection status and debug interactions.
• Custom Handshake Parameters: Apidog lets you customize the handshake parameters, including Headers, Params, and Cookies.
• Documentation and Collaboration: It also includes features to document your WebSocket APIs in Markdown format, making it easy to share with your team.

Why Choose Apidog?

Apidog simplifies the entire WebSocket testing process by providing a specialized environment for real-time API testing. It’s a great alternative for developers who need a powerful tool that focuses on both HTTP and WebSocket APIs, without the complexity of Postman’s interface.

Explore Apidog for Backend developers: Debug APIs

Explore Apidog for QA engineers: Test APIs

2. WebSocket.org — WebSocket Test Client

WebSocket.org provides a simple, user-friendly WebSocket Test Client that can be accessed directly through a browser. It is entirely free and requires no installation. This makes it a quick and convenient option for testing WebSocket APIs on the fly.

Key Features:

• Direct Browser Access: No installation is required, just visit the WebSocket.org website and start testing.
• Basic WebSocket Testing: You can enter the WebSocket server URL and establish a connection directly from the interface.
• Send and Receive Messages: Once the connection is established, you can send text messages and monitor responses in real-time.
• Connection Monitoring: WebSocket.org provides visual feedback about connection status, including whether the connection was successfully established.

Why Choose WebSocket.org?

If you need a fast and lightweight tool for testing WebSockets without the complexity of full API development platforms, WebSocket.org offers an easy-to-use interface for basic WebSocket testing. It’s perfect for quick experiments or simple testing.

3. Smart Websocket Client — Chrome Extension

The Smart Websocket Client is a Chrome extension designed specifically for testing WebSocket APIs. It’s lightweight and offers a simple interface for connecting to WebSocket servers and testing message exchanges.

Key Features:

• Browser-Based Testing: It’s an easy-to-use extension for Chrome, eliminating the need for separate applications or setups.
• Connect to WebSocket Servers: You can connect to WebSocket servers directly using the ws:// or wss:// protocols.
• Message Sending: Send and receive messages in real time. The interface lets you view incoming and outgoing messages in a clear, organized way.
• Connection Feedback: The extension provides clear status indicators about connection states (e.g., open, closed, or errors).

Why Choose Smart Websocket Client?

If you’re looking for a browser-based solution for WebSocket testing, the Smart Websocket Client is a solid choice. It’s especially useful for those who prefer not to install additional software or want a simple, no-frills solution for testing WebSocket connections.

4. Wscat — Command-Line WebSocket Testing Tool

For developers who prefer command-line tools, Wscat is a WebSocket testing tool that allows you to interact with WebSocket servers directly from your terminal. It’s a free, open-source tool that supports both WebSocket and secure WebSocket (wss://) connections.

Key Features:

• CLI-based Tool: Wscat allows developers to connect to WebSocket servers via the command line, offering a lightweight and scriptable solution.
• Real-time Communication: You can send and receive messages over WebSocket, with output displayed in the terminal.
• Custom Headers: You can set custom headers during the WebSocket handshake for advanced testing scenarios.
• Cross-Platform: Works on various operating systems including Windows, macOS, and Linux.

Why Choose Wscat?

If you are comfortable with the command line and prefer minimalistic, scriptable solutions, Wscat is a great tool for quickly connecting to and testing WebSocket endpoints. Its open-source nature and active development make it a popular choice for developers in need of a fast, no-fuss WebSocket testing tool.

5. Postman — A Familiar Tool for WebSocket Testing

Postman is a popular API testing tool that many developers use for testing RESTful APIs. In addition to HTTP requests, Postman has also added WebSocket testing functionality, allowing developers to use the same tool for both HTTP and WebSocket APIs.

Key Features in terms of Websocket:

• WebSocket Support (Beta): Postman recently introduced WebSocket support as a beta feature, enabling users to establish WebSocket connections with ws:// and wss:// URLs.
• Send and Receive Messages: Once connected, you can send messages and receive responses in real time, just like in other WebSocket testing tools.

Why Choose Postman?

Postman is ideal for developers who are already familiar with its interface and have been using it for RESTful API testing. It is a versatile tool that provides a single interface for both HTTP and WebSocket testing, making it an attractive option for those who want to test multiple types of APIs in one place.

Conclusion

Testing WebSocket APIs doesn’t have to be a complicated process, and thankfully, there are several free tools available for developers looking to do so — without relying on Postman. Whether you prefer a browser-based solution like WebSocket.org, an all-in-one tool like Apidog, or a command-line approach with Wscat, there’s a tool for every need.

Each of the tools we discussed today has its own unique strengths. If you’re working with WebSocket in a professional environment and require additional features like custom handshake parameters, real-time message tracking, and collaboration tools, Apidog is the most comprehensive option.

For quick testing and simple projects, WebSocket.org and Smart WebSocket Client are lightweight solutions. And for those who like working from the command line, Wscat is an excellent choice.

Explore these free tools and find the one that fits your testing needs — no matter the complexity of your WebSocket API.