This diploma thesis compares Grails and Play frameworks. The main goal of the thesis is to provide its readers a comprehensive view of benefits and disadvantages of the two frameworks using thorough comparison.In the first part of the thesis Grails and Play are introduced. In the next part the author defines criteria for comparison and analyses the sample application. The crucial part of this work is the comparison of the frameworks and their results. This work is intended to make the decision proces easier for developers who wants to choose one of these frameworks for their projects.