Educational online technologies (EOTs) have revolutionised the delivery of online education, making a large contribution towards the global increase in demand for higher learning. Educationalists have striven to adapt through knowledge development and application of online tools, but making educationally sound choices about technology has proved challenging, amidst the extensive and largely unclassified range of tools. The absence of a taxonomy comprehensive enough to guide EOT choice is a concern, given the current extent of online activity. This paper addresses this issue by proposing a new taxonomic framework of EOTs called the Pentexonomy. Developed by augmenting five existing taxonomies, the Pentexonomy synergises a range of perspectives to produce a robust and multi-dimensional classification which facilitates effective decision-making on EOT activity.