Reading on a computer screen can cause the reader to have a poor experience if the electronic reading material does not have sufficient contrast, legible font type, and large enough font size. Prolonged use of electronic reading material can lead to visual fatigue, reduced reading speed, and reduced reading performance. Web Content Accessibility Guidelines (WCAG 2.0) were developed to mitigate these issues caused by electronic reading material and ensure that web content is accessible for all users. Adults typically experience reductions in near vision and visual acuity as they age, so they can have more pronounced issues when reading on a computer screen if the material is not designed for accessibility. The ability to customize web pages allows for users to make changes to font size, font type, and foreground/background contrast that fit their specific needs. The current study examined whether the ability to customize electronic reading material improves reading task performance, reading speed, and usability, as well as reduces visual fatigue. Twenty younger adult (18 to 22 years of age) and twenty older adult (45 to 69 years of age) participants read short, medium, and long passages and answered reading comprehension questions after each passage. Each participant had the ability to customize the webpage of half of the passages based on pre-selected customization schemes that vary based on font type, font size, and contrast. This study employed a 2 (Customization: Customization vs Non-Customization) × 3 (Passage Length: Short: 550 words vs Medium: 800 words vs. Long: 1200 words) × 2 (Age Group: Younger: 18 – 22 years old vs. Older: 45 – 69 years old) mixed design, with age group as the between-subjects variable and customization and passage length as within-subjects variables. Reading task performance, reading speed, usability ratings, and reports of visual fatigue were measured for each condition. It was hypothesized that customization will result in a reduction in reading time and accuracy, higher usability ratings, and lower reported levels of visual fatigue with the largest effect being for older adults. The results showed, however, that the use of customized text elements did not improve comprehension scores or reduce reading times. Moreover, the significant interaction of customization and age group showed that older adults showed little difference in comprehension scores in the customized and non-customized conditions, but younger adults had higher comprehension scores in the non-customized condition than the customized condition. These results suggest that customization may not be beneficial to either younger or older adults, so designers should include accessible text options as default settings rather than letting users customize for themselves.