Describe your system in plain English and AI drafts an editable diagram — or sketch it yourself on an infinite canvas. Architecture, sequence, class, ER and state, with hand-drawn style, smart connectors, and real-time collaboration. Free to start, no signup.
A working system-design diagram loads below. Grab a box and the arrows follow. Nothing is saved to an account.
Type a sentence and sysdraw drafts a real diagram — native shapes and bound arrows, not a flat image. Then refine it in chat, or select part of the canvas and ask for a change. E-commerce backend: browser → API gateway → auth and orders services; orders writes to Postgres and caches in Redis.
General whiteboards lack the primitives; heavyweight tools feel like form-filling. sysdraw sits in the middle.
A searchable icon library — services, queues, databases, caches, gateways — plus smart connectors that snap to anchors, route around obstacles, and follow shapes as you move them.
Dedicated modes for sequence diagrams (lifelines, activations, loop / alt / opt / par fragments), UML class, ER, and state — not just generic boxes and arrows.
Model real business processes: pools and lanes, tasks and sub-processes, start / intermediate / end events, exclusive / parallel / inclusive gateways, data objects, and typed sequence / message flows.
Paste Mermaid and get a clean, editable, hand-drawn diagram: flowchart, sequence, class, state, ER, gantt, pie, and gitGraph.
Edit together on a CRDT-synced canvas with live cursors and selections, element-pinned comment threads, @mentions, and email invites with view / comment / edit roles.
Start a voice room inside any shared scene and walk through a design while you point, draw, and edit together — with live mute and who's-talking indicators, plus studio-grade noise suppression. View-only guests can join the call too.
Toggle between sketchy (Rough.js) and clean strokes per element. Hand-written Caveat labels or geometric Inter — your call, on an infinite dotted canvas.
Local-first auto-save means it works offline and needs no signup to start. Sign in and everything syncs across your devices automatically.
Publish a view-only link, or drop a live diagram into Notion, a blog, or a README with an embed iframe. Export any scene to PNG, SVG, PDF, or JSON in one click.
No signup needed to sketch. Sign in to sync across devices, and go Pro for more scenes, watermark-free exports, and Mermaid import.
Start sketching — and taste AI
For everyday system designers Stress-test your architecture live
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no signup · nothing to install