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A freehand whiteboard and AI diagram conversion

DiagramaHub v0.6.0 adds a freehand whiteboard inspired by Miro and Excalidraw, and uses AI to convert diagrams between Mermaid, PlantUML, D2 and DBML.

Not every idea starts as code. Sometimes you need to sketch a few boxes and arrows to think, and sometimes you already have the diagram written, just in the wrong language for where it's going. Version 0.6.0 covers both: a freehand whiteboard and AI-powered conversion between diagram languages.

A new diagram type: the whiteboard

Alongside Mermaid, PlantUML, D2 and DBML, you can now create a Freehand diagram: an Excalidraw-like canvas where you draw directly with:

  • Basic shapes: rectangles, diamonds and circles.
  • Arrows, lines, text and freehand paths.
  • A toolbar with color pickers and stroke width controls.

If you run a self-hosted instance: the canvas state is stored as JSON in the same content field every other diagram uses, so no schema migration is needed.

The best of Miro and Excalidraw

A whiteboard lives or dies by how it feels, so we borrowed what works best in Miro and Excalidraw:

  • Undo and redo (Ctrl+Z, Ctrl+Shift+Z or Ctrl+Y) with toolbar buttons and a 100-step history.
  • Inline text editing, no browser prompt: multi-line support, text elements that grow as you type, and text inside shapes always centered.
  • Keyboard shortcuts for every tool, Ctrl+D to duplicate, arrow keys to nudge and F to fit to content.
  • A hand tool and Space+drag panning.
  • Align and distribute for multi-selections.
  • Group and ungroup (Ctrl+G / Ctrl+Shift+G), with clicks that select the whole group.
  • Rotate shapes and text with a handle, snapping to 15° while holding Shift. Connected arrows follow the rotated anchors.
  • Miro-style red alignment guides that snap while you drag or draw.
  • A contextual style panel right next to your selection.
  • A drag-to-erase eraser, dashed lines, start/end arrowheads, rounded corners and font size controls.

Convert between Mermaid, PlantUML, D2 and DBML

Got a Mermaid diagram but your team documents everything in PlantUML? A schema you'd rather have in DBML? You can now convert a diagram to another language using the AI provider you already set up in DiagramaHub (your own API key, just like every other AI feature).

Before anything changes, you see the original and the result side by side, along with warnings about potential incompatibilities between the languages. Conversion is preview-only: nothing is saved until you accept it. Once you do, the diagram is automatically re-centered on screen.

sequenceDiagram
    participant U as You
    participant D as DiagramaHub
    participant AI as Your AI provider
    U->>D: Convert to another language
    D->>AI: Original diagram and target language
    AI-->>D: Converted diagram
    D-->>U: Side-by-side preview with warnings
    U->>D: Accept
    D-->>U: Updated and re-centered diagram

Other changes

  • The editor now opens with the folders/files sidebar closed; it shows up when you click the folder icon next to the diagram title.
  • For self-hosters: the frontend moved from npm to pnpm for faster installs and better disk efficiency.

Try it

Create a Freehand diagram or convert an existing one in DiagramaHub Cloud. If you self-host, upgrade to 0.6.0. Everything else is in the changelog.