# Validating HTTP responses

Talend Cloud API Tester allows you to test the behavior of your APIs.

You can test your API by using Assertions to verify that a certain part of an HTTP response matches your expectations. You can define assertions against the following response characteristics:

* Status code
* Headers
* Body length
* Duration
* Status message
* JSON body (using JSON Path)
* XML body (using Xpath)
* Body content

Assertions are validated in real-time, meaning that they are re-evaluated when you run the request and when you update them.

![Assertions tab.](https://help.qlik.com/talend/en-US/api-tester-user-guide/Resources/images/oco1572277886906_LowRes.png)

Assertions leverage operators in order to compare values and check the existence or inclusion of certain values.

For example:

* Status code equals 200
* Duration (ms) less than 200
* Body content exists
* The element located at JSON path $.id in the JSON body equals 12345

Assertions are a solid base to test your API, but you need them to be dynamic. Dynamic assertions allow you to test that the header Content-type of the response is equal to the header Accept of the request for example. You can create dynamic assertions with expressions.

### In this section

* [Assertions](https://help.qlik.com/talend/en-US/api-tester-user-guide/Cloud/assertions)
* [JSON path](https://help.qlik.com/talend/en-US/api-tester-user-guide/Cloud/jsonpath)
* [XPath](https://help.qlik.com/talend/en-US/api-tester-user-guide/Cloud/xpath)