An example system includes a processor to crawl a plurality of web pages of a web application to be tested. The processor is to also receive an intercepted input to the web application and an output from a web application associated with each crawled web page. The processor is to further detect testable elements in the intercepted input and the output. The processor is also to generate a fingerprint for each web page based on the detected testable elements. The processor is to generate a list of clusters comprising one or more similar web pages based on the fingerprints. The processor is to test a single web page from each cluster.