Merdown

Write Markdown, preview Mermaid diagrams live, and visually diff Mermaid diagrams across your Git history.

Under 20 MB. No sign-in. Everything stays on your Mac.

Explore Merdown

Merdown editing Markdown beside a rendered local document and Mermaid diagram

Local filesGit-awareMermaid 11macOS 13+

Git-aware diagrams

Visual Mermaid diffs from your Git history

Compare Mermaid diagrams across Git commits and see changes directly on the rendered diagram. Merdown shows the visual diagram change alongside the underlying source diff.

Review additions and removals in the source diff
Toggle the visual diff on the rendered diagram
Browse Git commits without changing your working files

Merdown visual Mermaid diff highlighting added and removed connections beside Git commits

Mermaid support built in

Start with a familiar diagram and keep working

Create flowcharts, sequence diagrams, class diagrams, state diagrams, entity-relationship diagrams, architecture diagrams and more

Built-in starters for common Mermaid diagram types
Live preview alongside the editor
Pan, zoom, fit and a minimap for larger diagrams

Merdown editing a request-routing Mermaid flowchart beside its live preview and zoom controls

Everything local, with no account required

A small client for the full Mermaid workflow

Edit Mermaid and Markdown, review Git changes and work with local files without creating an account or moving documents to a cloud workspace

< 20 MBlightweight download