Webpage reading is ubiquitous in daily life. As Web technologies allow for a large variety of layouts and visual styles, the many formatting options may lead to poor design choices, including low readability. This research capitalizes on the existing readability guidelines for webpage design to outline several visuo-typographic variables and explore their effect on eye movements during webpage reading. Participants included children and adults, and for both groups typical readers and readers with dyslexia were considered. Actual webpages, rather than artificial ones, served as stimuli. This allowed to test multiple typographic variables in combination and in their typical ranges rather than in possibly unrealistic configurations. Several typographic variables displayed a significant effect on eye movements and reading performance. The effect was mostly homogeneous across the four groups, with a few exceptions. Beside supporting the notion that a few empirically-driven adjustments to the texts' visual appearance can facilitate reading across different populations, the results also highlight the challenge of making digital texts accessible to readers with dyslexia. Theoretically, the results highlight the importance of low-level visual factors, corroborating the emphasis of recent psychological models on visual attention and crowding in reading.