A method of crawling a graphical user interface (GUI) based application may include performing a first-time crawl of a first sequence of actions of the GUI-based application. The first-time crawl may be a first time that the first sequence of actions is crawled. Further, the first sequence of actions may be a prefix of a second sequence of actions that includes one or more additional actions than the first sequence of actions. The method may also include extending the first-time crawl by the one or more additional actions such that the second sequence of actions is crawled during the first-time crawl. Further, the method may include determining a first input/output sequence associated with the first sequence of actions based on the first-time crawl. Additionally, the method may include determining a second input/output sequence associated with the second sequence of actions based on the first-time crawl.