This article tests the hypothesis that the internet is exacerbating an existing knowledge gap in Australia. The data come from the Australian Election Study, which has measured voters’ political knowledge and internet use since 2001. The results support the knowledge gap hypothesis: while internet access is expanding, consumption of political information online is narrowing among a younger, better educated and politically interested group, and is increasingly associated with higher levels of political knowledge. The internet is therefore reinforcing the advantages of the most knowledgeable while increasingly failing to draw in the most politically uninterested. Despite hopes that the internet would lead to a more informed demos, these findings suggest that it is exacerbating current participatory biases.