AiLounge Tools

Local Hand-Drawn Whiteboard

Organize sketches with shapes, arrows and Chinese text locally in your browser, then export .excalidraw / SVG backups — no login, no upload, no collaboration.Processed locally · not saved by default

Whiteboard (local scene model)

Compose deterministic scenes from shapes + arrows + Chinese text; two presets, .excalidraw import/serialization round-trips, an explicit local draft, confirm-before-replace, a 48px brand bar and safety-policy audits.

Run in browser

Inputs and parameters

Real example

action=roundtrip, presetId=flow-sketch
Input scene: rectangle "Start" (80,120,160×72), "Refine" (320,120), "Review" (560,120), arrow flow-a1 points=[[0,0],[80,0]], Chinese label "Flow sketch: requirements → refine → review".
→ serializeScene → parseSceneDocument → {"positionsEqual":true,"elementCount":9,"chinesePreserved":true,"arrowPointsPreserved":true}; after re-import (80,120) and arrow points are byte-for-byte identical.

Limits and failure handling

The real Excalidraw React/Canvas engine, freehand strokes, PNG rasterization, self-hosted fonts, 390/768/1440 widths and on-device gestures are NOT integrated / NOT verified; this operation provides a deterministic scene model and testable contracts only. PNG export throws PNG_RASTERIZER_UNAVAILABLE without an injected rasterizer and never fabricates pixels.

FAQ

What are the two presets?

flow-sketch (start → refine → review, 9 elements) and product-idea (users / value / flow / risks, 15 elements), both with Chinese text and bound arrows.

What happens to imported remote images?

files are dropped with a REMOTE_FILES_DROPPED warning; image elements fail validation as REMOTE_IMAGE_REJECTED, with no fetching.

Do draft keys affect other sites?

No. The namespace is al:draw:v1:* and cleanup matches only that prefix; tests verify other-site keys keep their values.