Abstract
The COVID-19 pandemic has resulted in a step change in the scale of sequencing data, with more genomes of SARS-CoV-2 having been sequenced than any other organism on earth. Previous webbased tools for phylogenetic exploration were not able to directly scale to this size of tree. We have developed Taxonium, a new tool that uses WebGL to allow the exploration of trees with tens of millions of nodes. Taxonium allows visualisation of mutation-annotated trees, where the genotypes at each internal node are indicated, and also links each node to associated metadata. An optional server-side backend permits rapid loading for widely used datasets, while a client-only mode allows the exploration of niche or sensitive data. Taxonium is an open-source tool which can be applied to any large tree. We provide an application for exploring a public tree of more than five million SARS-CoV-2 sequences at cov2tree.org, the broader Taxonium tool at taxonium.org, and source code at github.com/theosanderson/taxonium.
Competing Interest Statement
The authors have declared no competing interest.
