Plagiarism is a socially negative phenomenon which is particularly undesirable in the scientific and educational circles. The legal framework aknowledges the problem of plagiarism, but relatively unsuccessfully sanctions and detects it. Jurisdiction is usually shifted among various bodies with different levels of authority without clearly defined responsibilities and usually it is completely unclear who should take what actions for sanctioning as well as who starts the process of proofing. Simple, fast, effective and easily accessible application would contribute in preventing such behavior. Implementation and comparison of Humming and Lenenshtein distance and also Jaccard coefficient through creation of an application that would test their capabilities and limitations gives a clear overview of possible directions for further development of application support for computer-assisted detection of plagiarism. The potential for improvement gives more value to the results of this work.