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Published in eLife All Contributors

Taxonium is a tool for exploring trees, including those with millions of nodes.

How do I..

visualise my own Newick phylogeny?

Upload a Newick file to, and optionally a metadata file in CSV or TSV format. If using a metadata file the leftmost column must contain names of the nodes as in the tree.

explore the global SARS-CoV-2 phylogeny?

Visit which uses Taxonium to allow you to explore a tree built by researchers at UCSC using public data contributed by researchers across the world to the INSDC databases.

build my own mutation-annotated tree to explore in Taxonium, or add my own metadata to an existing phylogeny?

Use UShER to build a mutation-annotated tree. Then use taxoniumtools to convert it to a Taxonium format you can upload to the interface at

You can also use taxoniumtools to add your own metadata to the existing public phylogeny.

Find out more in 📚 the documentation.

load really huge trees?

For trees larger than about 6M tips, loading local trees in the browser at can be unreliable on some systems due to browser memory limitations. To avoid these issues, use the Taxonium desktop app.

use Taxonium in my own web application?

Use the Taxonium component.

See Taxonium in action

Citing Taxonium

Sanderson, T (2022). Taxonium, a web-based tool for exploring large phylogenetic trees. eLife, 11:e82392

N.B. If you are citing the tree displayed at, please cite the UCSC tree (.. and ideally Taxonium too if you relied on it for exploration)

There is a separate paper for the Treenome Browser feature (Kramer et al., Bioinformatics, 2022).


Taxonium is structured as a 'monorepo' containing a number of components:

  • taxoniumtools - a Python package that lets you easily generate Taxonium files from Usher protobuf files
  • taxonium_component - a React component that implements the Taxonium tree explorer
  • taxonium_website - The Taxonium website found at, a wrapper around taxonium_component
  • taxonium_backend - a server-based backend that allows Taxonium trees to be explored without the user downloading the full tree (N.B. Taxonium can also be used without this backend, with static files acccessed in taxonium_website)
  • taxonium_data_handling - this is a node package upon which both the web client and the backend depend (it handles core logic common to both)


We welcome contributions. We require that that all contributors follow the Contributor Covenant Code of Conduct.


Taxonium development was initiated and is led by Theo Sanderson at the Francis Crick Institute.

Theo Sanderson

💻 📖 🎨 🤔 🚇 🚧

We are very grateful to our contributors:

Alex Kramer

💻 🎨 🤔

Angie Hinrichs

🤔 🔣

Richard Goater

🎨 💻

Chaoran Chen


Cornelius Roemer


Sung Kwon


Koorous Vargha


Alex Kramer at UCSC built the Treenome Browser component within Taxonium, described here.