Software testing is one of the most important stages of the Software Development Life Cycle. There are various software testing approaches that are often used and useful in finding errors in software, two of them are Automation Testing and Exploratory Testing. Graphic User Interfaces (GUI) is one area of Automation Testing and Exploratory Testing. GUI testing involves the execution of widget-related events. Dynamic web pages are a type of web page that is currently used by most web developers and has a complex GUI. GUI testing needs to be done on dynamic web pages, and complex GUI structures will be a challenge for the tester to find the right way to test dynamic web pages. To solve the problem, this Thesis does a comparative analysis between two methods, Automation Testing and Exploratory Testing. Those methods are chosen because the two methods have different emphases but both are fully compatible. The analysis is done by calculating the average execution time and defect density from the two methods carried out. The result of the analysis shows that automation testing has the same good ability to detect defects. But, automation testing is the faster method than exploratory testing.