View NEX files in your browser
The file MrBayes, BEAST, PAUP* and Mesquite keep their trees in. Open one right here with its trees drawn. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your tree opens drawn with its branch lengths, rectangular or circular, its support by each clade.
- Rectangular or circular • Branch lengths, a scale and support
- Fold a clade • A click on its node
- Find a name • Every match marked
- Export • Save as SVG, PNG or Newick
About NEX
David Maddison, David Swofford and Wayne Maddison published NEXUS in 1997 for PAUP* and MacClade, and MrBayes, BEAST, Mesquite and SplitsTree read and write it. A file starts with #NEXUS and holds blocks: TAXA for the names, DATA or CHARACTERS for an alignment, and TREES for one tree or many.
A TREES block often has a TRANSLATE table that numbers the taxa so its trees stay short, and MrBayes and BEAST write each tree's posterior and other notes in square brackets. A run's output can hold thousands of trees.
Filepeek reads it in your browser and draws its trees with their tips named from the TRANSLATE table, rectangular or circular, with their branch lengths and support, one at a time from a list when there are many. A click on a node folds its clade, Find marks the names that match, and Export saves the tree as SVG, PNG or Newick. A NEXUS of an alignment alone opens as its text.
NEXUS file
.nex • .nexus • .nxs
Format
- MIME type
- text/x-nexus
- Made by
- David Maddison, David Swofford and Wayne Maddison
- Released
- 1997
Inside the file
- Blocks
- TAXA, DATA, TREES and more
- Trees
- Newick inside a TREES block
- Names
- Numbered in a TRANSLATE table
- Notes
- In square brackets
Opens in every browser
Filepeek opens NEXUS files in Chrome, Edge, Firefox and Safari. On their own, browsers download them or show them as text.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Apps that open NEX
- WindowsFigTree, free • Mesquite and PAUP*
- MacFigTree, free • Mesquite
- iPhone and iPadNo app opens it
- AndroidNo app opens it
Questions
My NEXUS file holds many trees. Which one shows?
The first, with the others in the list beside Find, up to 1,000 of them. Pick one to draw it, and Save this tree as Newick saves the one on show.
Why do my tips show numbers?
A TRANSLATE table numbers the taxa, and Filepeek names them from it. A tree with numbers and no TRANSLATE table shows them as they are.
Can I turn a NEXUS tree into Newick?
Yes. Choose Export, then Save this tree as Newick, for FigTree, iTOL or any tool that reads Newick.