Diagram Guidelines

Preferred file format

For complex diagrams, use the .drawio.svg format.

Files with the .drawio.svg extension are SVG files with embedded draw.io source code. Using that format lends itself to a developer-friendly workflow: it is valid SVG, plays well with git diff and can be edited in lock-step using various online and offline flavours of draw.io. If you use VS Code, you can use an extension for draw.io integration.

Files in the .drawio.svg format can be processed offline.

Embedding a diagram into Markdown

To embed a .drawio.svg file into Markdown, use the same syntax as for any image. Example: ![My diagram](my-diagram.drawio.svg)

Mind that GitHub doesn’t allow styling in Markdown documents. Where styling is allowed (e.g. in the exported brew.sh version of the documentation), always set a background colour of white for the diagram. That’s the colour draw.io assumes, and keeps the diagram easy to read in dark mode without further customization. You can use the CSS selector img[src$=".drawio.svg"] for styling.


Example for an SVG image embedded into Markdown:

![Example diagram: Managing Pull Requests](/assets/img/docs/managing-pull-requests.drawio.svg)


Example diagram: Managing Pull Requests

Example for styling (where allowed):

img[src$=".drawio.svg"] {
  background-color: white;
  margin-bottom: 20px;
  padding: 5%;
  width: 90%;

@media (prefers-color-scheme: dark) {
  img[src$=".drawio.svg"] {
    filter: invert(85%);
    -webkit-filter: invert(85%);

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Licensed under the BSD 2-Clause License.