Hey Product Hunt 👋 I write my diagrams the way I write code: in text. Mermaid for flowcharts, PlantUML for class diagrams, D2 when I want it to look good, Graphviz DOT when the graph is big enough that I want a real layout engine. None of which renders on my iPhone or iPad. So I wrote the renderer instead. DiagramKit, my engine, parses all four formats into a native representation, lays them out with real graph-layout engines, and draws them as SwiftUI views. No WebView, no JavaScript runtime, and the app makes no network calls (if your files live in iCloud Drive, the system syncs them). • Paste anything; it works out which language it is. • Open a README and every fenced mermaid / d2 / ```dot block renders inline, prose in between. • Press space on a diagram in the Finder for Quick Look; in Files and Finder, diagram files get a rendered thumbnail instead of a page icon. Viewing is free, forever: all four formats, every device, no account, no trial. Editing, export, Markdown mode and the share extension are a one-time $14.99. No subscription. Family Sharing on. One purchase covers iPhone, iPad and Mac. DiagramKit is also an SDK I license to other apps; Diagrammar is its live demo. Tell me which diagram language you actually use, and what breaks. I test against a 700-file corpus and still expect your file to find the bug. — Bakhtiyor

Diagrammar

Mermaid, PlantUML, D2 & DOT — native on iPhone, iPad & Mac

Mermaid, PlantUML, D2 & DOT — native on iPhone, iPad & Mac