Phylogenetic Tree Maker
Paste a tree in Newick format and get a clean rectangular tree: a phylogram with branch lengths drawn to scale, or a cladogram that shows the branching order alone, with tip labels lined up in a column. Support values, clade names and a scale bar are drawn for you, and you can download the figure as SVG or PNG. It draws a tree you already have; it does not build one from sequences. Runs entirely in your browser — nothing is uploaded.
Nested parentheses with optional names, branch lengths after colons and support values on internal nodes, ending in a semicolon. Quote names that contain spaces or punctuation; [comments] are ignored.
5
Tips
4
Internal nodes
0.0893
Total branch length
0.0279
Longest root-to-tip distance
Every tip is the same distance from the root, as in a tree built with a molecular clock.
Show the tree as a table
| Node | Depth | Branch length | Support | Tips below |
|---|---|---|---|---|
| (internal node) | 0 | 5 | ||
| (internal node) | 1 | 0.0111 | 100 | 4 |
| (internal node) | 2 | 0.0066 | 88 | 3 |
| (internal node) | 3 | 0.0037 | 95 | 2 |
| Human | 4 | 0.0065 | 1 | |
| Chimpanzee | 4 | 0.0065 | 1 | |
| Gorilla | 3 | 0.0102 | 1 | |
| Orangutan | 2 | 0.0168 | 1 | |
| Gibbon | 1 | 0.0279 | 1 |
Title and figure style
Takes the title out of the image and sets the figure number in bold and the title in italics above it — the APA 7 layout.
How to Use the Phylogenetic Tree Maker
- 1. Paste your tree. Use Newick format, the text output of most tree-building programs (the .nwk, .tre or .treefile file). The example loaded in the box is a small tree you can edit.
- 2. Choose phylogram or cladogram. A phylogram draws each branch as long as its branch length; a cladogram ignores lengths and lines every tip up at the right.
- 3. Set the details. Write branch lengths on the branches, show support values and clade names, align the tip labels in a column with dotted guides, put species names in italics, and order the clades as written or ladderized.
- 4. Download. Save the tree as SVG or PNG, or tick APA style figure to move the title out of the image. Copy Newick puts the cleaned-up tree text on the clipboard.
What Newick Format Looks Like
Newick writes a tree as nested parentheses. Each pair of parentheses is a clade, the names inside are its members, and a number after a colon is the length of the branch leading to that node. The format was agreed in 1986 at a dinner at Newick's restaurant in Dover, New Hampshire, which is where the name comes from. The tool reads the following:
| Part | Example | Meaning |
|---|---|---|
| Clade | (A,B) | A and B share a common ancestor |
| Branch length | A:0.12 | the branch to A is 0.12 long, in whatever unit the tree was built with |
| Support value | (A,B)95 | a number on an internal node, such as a bootstrap percentage |
| Clade name | (A,B)Primates | a name on an internal node |
| Underscore | Homo_sapiens | an underscore in an unquoted name is shown as a space |
| Quoted name | 'Homo sapiens (human)' | single quotes allow spaces and punctuation; write a quote as two quotes |
| Comment | [anything] | ignored, including program annotations such as [&rate=1.2] |
| End | ; | ends the tree; a missing final semicolon is accepted |
Names and numbers may be separated by any amount of whitespace or line breaks. If the input holds several trees, the first is drawn and the others are counted. If something is wrong, the message gives the character position, so a missing closing parenthesis is easy to find.
Phylogram or Cladogram
- Phylogram. The horizontal distance from the root to a node is the sum of the branch lengths along the way, so you can read evolutionary change or time straight off the picture. The scale bar shows how long a given length is. Tips end at different places unless the tree is ultrametric, which happens when it was built assuming a molecular clock; the dotted guides run each tip out to its label.
- Cladogram. Branch lengths are ignored and only the branching order counts. Every tip ends at the same place, and a node's position depends on the longest chain of branches below it. Use it when the lengths are meaningless or you want to show relationships only.
- Ladderizing. Sorting clades by size, smallest or largest first, makes a tree easier to read without changing what it says. Rotating a node's branches never changes the relationships.
Worked Example
The default tree has five tips: ((((Human:0.0065,Chimpanzee:0.0065)95:0.0037,Gorilla:0.0102)88:0.0066,Orangutan:0.0168)100:0.0111,Gibbon:0.0279);. The branch lengths are made up for illustration, not taken from a published tree.
- It has 5 tips and 4 internal nodes. The tree is rooted at the open end of the outer parentheses, with Gibbon branching off first.
- The total of all branch lengths is 0.0893, and the longest path from the root to a tip is 0.0279.
- Every tip is 0.0279 from the root, so the tree is ultrametric and all five tips end at the same x on the phylogram, just as they do on the cladogram.
- The numbers 95, 88 and 100 on the internal nodes are drawn as support values. Human and Chimpanzee form a clade supported at 95.
Reading Support Values
A support value on a node says how well the data back that grouping. For bootstrap percentages, 70% or more is a common threshold for reasonable support (Hillis and Bull, 1993); for Bayesian posterior probabilities, 0.95 or more is a common bar. IQ-TREE suggests treating ultrafast bootstrap values of 95% or more and SH-aLRT values of 80% or more as reliable. Programs differ in what they report, so check the documentation of the one that built your tree. The tool shows the number exactly as written, including pairs such as 95/0.98.
Frequently Asked Questions
- What is Newick format?
- Newick is a plain-text way to write a tree with nested parentheses, names and branch lengths, such as (A:0.1,B:0.2,(C:0.3,D:0.4):0.5);. Almost every phylogenetics program can read and write it, which makes it the standard way to move a tree between tools.
- How do I read a phylogenetic tree?
- Read from the root at the left toward the tips at the right. Each fork is a common ancestor, and tips that share a more recent fork are more closely related. The order of tips from top to bottom means nothing, because branches can be rotated at any fork without changing the tree.
- What is the difference between a phylogram and a cladogram?
- A phylogram draws branch lengths to scale, so longer branches show more change or time. A cladogram shows only the branching order, and its branch lengths carry no meaning. Both show the same relationships.
- What do the numbers at the nodes mean?
- They are usually support values, such as bootstrap percentages or posterior probabilities, showing how well the data support that clade. A name instead of a number is a clade label. This tool treats an internal label made of digits, dots and slashes as support.
- Can I use a tree from MEGA, IQ-TREE, RAxML or BEAST?
- Yes, as long as you paste it in Newick format. IQ-TREE writes a .treefile, RAxML a .bestTree file, and MEGA can export Newick. Annotations in square brackets, as BEAST adds, are ignored. Nexus files must be converted first by copying out the tree line.
- Does this build a tree from DNA sequences?
- No. It only draws a tree you already have. Building one means aligning sequences and running an inference program, which this page does not do. Your tree text stays in your browser.