Holodeck
Present diagrams
Fullscreen pan/zoom, a minimap, and presentation mode that steps through every Mermaid in the doc.
Diagram drive online
Present the diagram, not a screenshot
SpecDown is a markdown viewer where Mermaid diagrams are first-class — zoom, pan, present, and export. No account. No editor chrome. Your architecture becomes a place you can fly through.
Drop Markdown File Here
or click to browse
or try a sample
or open from URL
Note: Some enterprise GitHub instances may require authentication and won't load here.
Live Mermaid in the viewport — expand it and fly
Any vector
Open from anywhere
Drop a file, open a folder, paste a raw URL, or paste a GitHub repo and pick the markdown.
Observer mode
Read, don't edit
TOC, find, split view, annotations, print/PDF. No vault, no account, no editor chrome.
Ground control
Get the desktop app
Signed & notarized on macOS. Windows and Linux builds on the same Releases page.
Download for macOS, Windows, or Linux