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In Development Last updated: August 2, 2023
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WebSocket Servers are preferred for real-time connections while overcoming the limitations of HTTP.

You get reliability and two-way communications to build real-time applications. However, before using it, you should test and troubleshoot it.

Let me highlight why testing WebSocket and the tools you can use is essential here.

Why Is WebSocket Testing Needed?

A woman testing and monitoring on the computer

A WebSocket API creates and manages WebSocket connections to the server.

So, if you test the API, you get to know any potential problems that might occur during the handshake (or connection). That’s why WebSocket testing is needed – to identify potential issues with the connection and explore how to fix them.

Technically, a couple of things need to be verified when WebSocket testing. Some of those are:

  • Status codes
  • Methods
  • Request and response
  • Response timings
  • Performance
  • Security
  • Business logic

For instance, the response time could matter to your use case or deployment; with testing, you learn about it and find ways to improve the situation.

Similarly, the security of WebSocket can also be put to the test by checking the vulnerability of the connection. If you can intercept the link and change the message, you will be able to know the problems.

Of course, all of this is possible with the help of testing tools. With the right tool, you can thoroughly test WebSocket APIs and their functions before deploying them.

Benefits of WebSocket Testing

The purpose of WebSocket testing already gives away the benefits that you get with it. To highlight separately, let me briefly mention them.

#1. Improving Security

A man is touching a padlock on a computer screen.

Whether it is WebSocket or anything else, connections should always be secure. For instance, the WebSocket protocol does not handle authorizations, but it has to be implemented at the application level to keep things safe. And, when you test the connections, you know more about the implementations.

#2. Improving Performance

A speedometer with the word performance.

While you test for everything, the performance also matters. You can think about taking the initiative to improve your performance as per the test results. It should help you in the long run if you can fine-tune the server better.

Similarly, debugging the connection will provide you with better insights into how reliable it is and how well it is maintained. Reliability is incredibly important for real-time communication; the better if you can improve it with testing.

You should always choose good WebSocket servers to ensure the best reliability.

One of the most significant benefits of WebSocket API testing is to test the business logic.

It means that the test cases show that it follows the documentation, design, and expected behavior of the web application. This makes sure that the WebSocket does not accept invalid input.

Challenges of WebSocket Testing

The most common challenge faced with WebSocket technology testing is browser incompatibility.

Yes, some browsers do not support WebSocket communication, and when this happens, the application will fall back to a different technique (long polling). So, this adds a bit of complexity for testers to keep in mind about the compatibility of browsers and how the application handles the situation.

Of course, you can also use some cloud-based browser testing tools to get help with app testing.

Another challenge includes hardware issues, which refers to the situation where you need to have multiple servers to manage the load put forward by the WebSocket connections. If you do not have enough servers, the connection will close, affecting the performance.

Not to forget, it is tricky to collect response times during the testing phase for asynchronous calls.

Asynchronous calls refer to the situation where the server communication will depend on how/when the user interacts. It is often tough to know when it takes to get the message to the client, as per the user action.

To overcome all this, we need the best testing tool that provides us with enough insights comparable to the real world and equips the developers for all kinds of scenarios.

Here, let’s mention some excellent WebSocket testing tools along with their key features for you to try.

Pie Socket

piesocket web testing screenshot

Pie Socket offers managed WebSocket, utilized by various brands. Even if you do not use its services, you can use its PieSocket WebSocket tester. You can enter the URL to connect and test or install its browser extension to test an unsecured WebSocket.


  • Supports insecure WebSocket server
  • Socket.IO testing support
  • Browser extension available
  • Simple and quick

As a web-based WebSocket testing tool, you can use it to save time and get quick insights. However, it might not fit all kinds of testing use cases.


insomnia platform screenshot

Insomnia provides a dev-friendly platform with automation and plugin support to test APIs faster.

Test WebSocket APIs efficiently to integrate them as soon as possible into your applications. You can get started for free with core tooling access and collaboration feature for one project.


  • Supports multi-protocols
  • Collaboration
  • Good UI

You must opt for its paid plans for end-to-end encryption and more cloud project support.



Postman is a popular API platform to help you build and test APIs. You can do numerous things related to APIs ranging from documentation to test cases.

You can create a new WebSocket request or open a Socket.IO request. Postman provides a web panel to test things out, but it is recommended to use its desktop agent for the best user experience.


  • The web panel and desktop app for effective testing
  • Easy to use and understand
  • Good documentation

Whether you need to edit messages, select protocols, configure headers, and debug issues with the WebSocket connection, the log shows you all the essential information to let you quickly test. You can also refer to its documentation to know all about it.

Autobahn WebSocket

Autobahn is a fully open-source test suite to automate client/server implementations of the WebSocket protocol.


  • Automated test suite
  • Open-Source

It includes the essentials, compliance checking, and performance/limit testing. You can spin it up on a Docker image and use it for testing WebSocket clients and servers.


testing api with apic platform

apic is a free and open-source API testing solution. It helps you with designing your APIs and testing the APIs.


  • Free and open-source
  • Feature-rich

You can also generate API documentation and test reports to share with anyone. Furthermore, you get an API simulator feature to help you test/mimic the responses based on your API design.


burp suite by portswigger for websocket security

Remember that I mentioned improving the security side of things as part of testing benefits?

PortSwigger’s Burp Suite is focused on web security testing and supports WebSockets as part of its offering. You can analyze the responses, modify/check the messages, and rule out any vulnerabilities by scanning the WebSocket API.


  • Security-focused testing

Unlike other tools above, you can only try it for free by requesting a trial or purchasing it to use all the features.


A screenshot of the python performance dashboard.

Like the last tool, K6 is a specialized tool focused on load testing and identifying performance issues.

As I mentioned earlier, one of the challenges for WebSocket testing includes hardware limitations, including the lack of servers to handle the load required for WebSocket connections.

So, with K6, you test the performance, find the reliability issues, and fix them before they appear.


  • It helps investigate performance issues and improve them.

You can test it on your local system or cloud using the same script.


api dog screenshot

Apidog is a full-fledged API testing platform with a developer toolkit and automated tools to generate documentation, reports, and mock data to get insights.

You can design and debut WebSocket requests without any hassle. It is also compatible with Postman scripts, so you can build, test, and design using a combination of tools if needed.

Apidog is free to get started with limits to storage for all the essential functionalities. At the time of writing, it had plans to introduce paid tiers with extended features; you can opt for it if you find it.


  • Free to start
  • Compatible with postman

In addition to all these tools, there are a couple of browser-based tools, and you do not need to sign up or pay for anything.

These are not the usual testing tools to help developers with essentials, but only a part. So you can try it out.

WebSocket King

websocket king

WebSocket King is somewhat similar to PieSocket’s web tool. You have to enter the WebSocket URL and check the output for all sent/received messages.

It does not support Socket.IO connections. So, you will be limited to the raw insecure connections.

WebSockets Test

WebSockets Test is a web-based tool to check if your browser supports the protocol and a bit of detail about it, including proxy support and protocol version number.

WebSocket Testing is Essential

With the proper testing tool, you will have everything necessary to have reliable, secure, fast WebSocket connections.

Of course, the tool you require will vary on your use cases. So, feel free to try what works best for you.

Next, check out WebSocket servers for reliable real-time applications.

  • Ankush Das
    A computer science graduate with a passion to explore and write about various technologies. When he’s not writing, it is usually his cats who keep him busy.
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