This paper discusses the issue of comparing Java and Kotlin technologies based on the web application framework. The criteria taken into account for testing purposes are: execution time, memory usage, CPU load, database response in set time. A series of tests and their in-depth comparative analysis are carried out. For this case, tests and code analysis were carried out to draw comparative conclusions. The performance in terms of web frameworks, database response speed and tests implementation in different languages - in all these Kotlin proved to be less efficient. There is no significant difference between CPU load between individual easurements, the difference does not exceed 2%. Implementation in the Kotlin language has never achieved the best result in any group of measurements.