While browsing some websites, interface words changes to non-understandable letters

This problem is mainly faced while browsing or searching for research papers on many websites. Some website names are in their regular language, but the content of the web page is changed to unintelligible language characters.For example, many English web pages have "Sinhala" language characters but no meaningful words. That is, there are no language-translation words. There are only sloppy letters and cranky words.[