There are many good tools to test APIs with. Some of the most popular tools include:

• Postman is a popular API testing tool that is available for free. It is easy to use and can be used to test both REST and SOAP APIs.
• SoapUI is another popular API testing tool that is available for free. It is more powerful than Postman and can be used to test more complex APIs.
• Rest-assured is a Java-based API testing library that is open source. It is powerful and can be used to test both REST and SOAP APIs.
• JMeter is a load testing tool that can also be used to test APIs. It is more powerful than Postman and SoapUI, but it is also more complex to use.
• Karate DSL is a DSL (domain specific language) for API testing. It is open source and can be used to test both REST and SOAP APIs.

The best tool for you will depend on your specific needs. If you are looking for a free and easy-to-use tool, then Postman is a good option. If you are looking for a more powerful tool, then SoapUI or Rest-assured may be a better choice. If you need to test APIs under load, then JMeter is a good option. And if you want to use a DSL, then Karate DSL is a good option.