The aim of this article is to focus on user experience with DysHelper, the dyslexia assistive web extension designed for Czech and other phonetic languages. We conducted this research with university and high school students over 18 years old. Firstly, we describe the design of the extension (invented in 2016 at Masaryk University) and then focus on describing the various stages of the practical user experience, which consisted of individual user testing, the reading two types of texts, followed by discussion with users. The results indicate that the extension is generally welcomed. Although DysHelper has its limits, user experience research shows that it has a significant potential to affect reading problems positively and can be easily used, also in consideration of needs that may change over time.