Best app for capturing architecture sketches from a whiteboard.
Short answer
BoardSnap reads system architecture sketches from whiteboards — service boxes, API arrows, database icons, dependency labels — and produces a plain-English narrative describing the architecture plus any action items (TODOs, open decisions) identified in the sketch. It's purpose-built for engineers who whiteboard architecture and need the sketch in a Confluence or Notion doc immediately after.
## Why architecture sketches are hard to digitize
System architecture diagrams on whiteboards are unlike plain meeting notes. They have:
- Boxes representing services, databases, or components
- Arrows with labels indicating data flow, calls, or dependencies
- Annotations ("async?", "v2", "TODO", "TBD")
- Crossed-out or erased elements showing design evolution
- Sometimes color-coding for different layers or teams
A plain camera photo captures this, but it's hard to share with someone who wasn't in the room. The text is small, the arrows overlap, and the whole thing is perspective-distorted if you couldn't stand directly in front of the board.
## What BoardSnap does with architecture sketches
After a VisionKit-corrected capture, BoardSnap AI reads the sketch and produces:
Narrative description — A paragraph describing the overall architecture: what the main components are, how they connect, what direction data flows. This is the kind of description that goes in the "Architecture Overview" section of a Confluence page.
Action items — Annotations like "TODO", "TBD", questions in circles, and incomplete arrows get extracted as action items. Open decisions from the sketch become open items in the tri-state list.
Context from project history — If previous boards in the project established the tech stack or constraints, BoardSnap can reference those in its reading of a new architecture sketch.
## Limitations for architecture diagrams
BoardSnap is not a diagramming tool — it doesn't produce an editable diagram or a Mermaid/PlantUML output. The result is a narrative description and action list, not a structured graph. For teams who need an editable diagram, the workflow is: BoardSnap captures the description → engineer translates to Mermaid or Lucidchart. The capture step is the pain; the reformatting is a quick task once you have the text.
## When to use dedicated diagramming tools instead
If the architecture is complex enough to require ongoing maintenance as a living diagram, tools like Lucidchart, draw.io, or Mermaid in Notion are the right destination. Use BoardSnap to capture the whiteboard session; use the diagram tool to maintain the canonical version.
Frequently asked
Can BoardSnap output Mermaid or PlantUML diagram syntax?
Not natively — BoardSnap produces a natural language description of the architecture, not structured diagram syntax. However, you can paste the BoardSnap summary into ChatGPT or Claude and prompt it to convert the description into Mermaid or PlantUML. That two-step workflow works well for simple-to-medium complexity diagrams.
See it work in ten seconds.
BoardSnap is free on the App Store. Snap a board — get a summary and action plan.