An architecture diagram editorthat opens before the signup form.
The Datadef canvas is free to open and built for data: typed nodes, tables with real columns, KPIs, freehand notes, and 500+ tech icons. Every AI-generated diagram lands here fully editable.
Free · No account · 1 AI diagram and 2 AI edits a day · Saves in your browser
How it works
Open, draw, keep what matters
The free scratch pad is the full editor, not a demo with the good parts removed.
Open the scratch pad
One click, no account, no download. The scratch pad is the same editor as the full product, working on a canvas saved in your browser.
Draw it or generate it
Drag typed nodes, connect flow edges, sketch freehand notes. Or describe the system and let AI draft the first pass, 1 AI diagram and 2 AI edits a day, free.
Keep it when it matters
Start Pro when a diagram deserves to outlive the browser: cloud projects, version history, collaboration, and sharing, after a 7-day free trial.
Nothing comes out flat.
An AI-generated diagram is not a picture. It is the same editable canvas document, so you fix the one wrong edge instead of regenerating and hoping.
Inside the editor
Typed nodes, real columns, one canvas
Tables carry columns, KPIs carry definitions, zones nest, and column-level lineage draws in its own layer, so the flow picture stays readable.
The canvas: typed nodes, labeled flow edges, nested zones, and annotations.
The properties panel: select anything to edit its name, columns, colors, icon, and metadata.
What costs what
Free where you draw, paid where you keep
The editing is free. The plan is for what happens to a diagram after you close the tab.
In the scratch pad, free
- The full editor: every node type, edges, zones, annotations
- Freehand drawing and 500+ tech icons
- Column-level lineage between real table columns
- 1 AI diagram and 2 AI edits a day, and PNG export, no account
- Saves locally in your browser
With Pro
- Cloud projects that follow you across devices
- Published versions you can restore
- Real-time collaboration on the same canvas
- PNG and JPEG export, sharing links, live embeds
- Unlimited AI, $12/month or $96/year after a 7-day free trial
Honest answers
Is the editor actually free?▼
The scratch pad is. It is the same canvas as the full product, open to anyone with no account: unlimited manual editing, PNG, JPEG and JSON export, and 1 AI diagram and 2 AI edits a day. Cloud projects, versions, collaboration, and unlimited AI come with Pro, $12 a month or $96 a year after a 7-day free trial.
Where do scratch diagrams live?▼
In your browser. The scratch pad saves to local storage on your machine, so the diagram is there when you come back in the same browser. Clearing site data deletes it, and it does not follow you across devices. Cloud projects that do follow you are part of Pro.
Can I edit a diagram the AI generated?▼
Yes, all of it. Generation writes a regular canvas document, not an image: every node, edge, and zone it draws is selectable and editable, exactly as if you had placed it yourself. You fix the one wrong edge instead of regenerating and hoping.
What can I export?▼
PNG and JPEG images of the canvas, and the canvas itself as JSON you can import again. All three are free, on the scratch pad too. Live embeds and public links come with Pro, and an embed stays current in a wiki where a static export goes stale. There is no PDF export today.
What makes it a data diagram tool rather than a generic canvas?▼
Nodes are typed. A table holds real columns, a KPI holds a definition, and sources, pipelines, and consumption endpoints are distinct things. Column-level lineage is its own layer on top of flow edges, so the detail is real without cluttering the picture. A generic whiteboard makes you fake all of that with text boxes.
What needs Pro?▼
Cloud projects that persist beyond one browser, version history you can restore, real-time collaboration, sharing links, live embeds, and unlimited AI under fair use. Pro is $12 a month or $96 a year and starts with a 7-day free trial; cancel before it ends and you are not charged. Signing in without it gives the same free allowance as the scratch pad.
Open the editor and draw
No account, no download, no trial clock. The scratch pad is the full canvas, saved in your browser, with 1 AI diagram and 2 AI edits a day when you want a head start.