Free tools

Small, free tools for drawing and reading diagrams. No sign-up, and they run in your browser.

Mermaid converter

Paste Mermaid code, download PNG, SVG or an editable draw.io file.

12V wire size calculator

The right wire gauge for boats, RVs, vans and solar, in AWG or mm².

Flowchart examples

Nine flowcharts you can download as free draw.io templates.

VSDX viewer

Open Visio files in the browser and export them to PDF, PNG or SVG.

Symbol charts

What each symbol means, with SVG downloads and a draw.io library for each set.

Electrical symbols

Flowchart symbols

Floor plan symbols

And the main tool

Sketch2scheme turns a photo of a hand-drawn diagram (a flowchart, a wiring sketch, a floor plan, a whiteboard) into a clean diagram you can edit in draw.io.

See how it works