 This study examined the level of readability of information on HPV vaccines found on 100 websites using established readability scales and found that many websites had difficult reading levels. Websites with commercial URL extensions and those found using the search Gardasil had higher mean readability scores, suggesting that interventions aimed at improving the readability of online information could help increase parental approval of the vaccine. This article was authored by Sarah A. McLean, Kori H. Bash, Dana Ethan, and others.