JMeter, the most popular open source performance testing tool, can work with regular expressions, with the Regular Expression Extractor. Regular expressions are a tool used to extract a required part of the text by using advanced manipulations. Regular expressions are popular when testing web applications because they can be used to validate and to perform operations on a response from a web application.
In JMeter, the Regular Expression Extractor is useful for extracting information from the response. For example, when you request a page and then need to get a link from the page that was downloaded. Another use case is saving the extracted information to a variable, so it can be used later on in the performance test, for example when testing an application that uses token authentication, like CSRF/XSRF.
In this article I’m going to share how to use the Regular Expression Extractor in JMeter.