Question 1

Is it actually free?

Accepted Answer

Yes. SmartSLD is an independent project, not a funded startup — there is no paid tier hiding behind a door. Drawing and exporting are unlimited; the AI assistant has a per-user daily cap so the bills stay boring.

Question 2

Do I need an account?

Accepted Answer

Not to draw. The editor runs anonymously and keeps your work in the browser. A free sign-in adds the AI assistant, cloud projects and share links.

Question 3

What can I export?

Accepted Answer

DXF that opens cleanly in AutoCAD and friends, SVG and PNG for documents, and the diagram's JSON if you want to feed it into your own tools.

Question 4

What is a single-line diagram?

Accepted Answer

A single-line (one-line) diagram represents a three-phase power system with one line per circuit — sources, transformers, switchgear, protection and loads on a single sheet. It's the drawing everyone leans over in an electrical design review.

Question 5

Where does my data live?

Accepted Answer

Anonymous drawings never leave your machine. Cloud projects are stored with Cloudflare (D1 + R2). When you ask the AI something, the diagram is sent to the model for that request only.

Question 6

Is it open source?

Accepted Answer

The editor core is — sldeditor, MIT-licensed, on GitHub. SmartSLD wraps it with the AI assistant, cloud storage and sharing.

無料のオンライン電気単線結線図エディタ、AI搭載。