How is this different from the Diagram Toolkit?

This one you draw by dragging; that one you write as text. Use this for a quick sketch or a layout that has no regular structure, and Mermaid for anything that belongs in version control.

Where are my saved boards kept?

In your own browser's storage on this machine. That means they survive closing the tab, but they do not follow you to another computer or another browser, and clearing site data removes them. To keep a board safe, or move it to another computer, download it as a board file (JSON) from Boards and open it here again later.

Do the connectors stay attached when I move a shape?

Yes. Connect links two shapes rather than drawing a loose line, so the line follows them around.

Should I export PNG or SVG?

SVG if it is going into a document or might need resizing, since it stays sharp and keeps text as text. PNG for pasting into a chat or a slide.

Is anything uploaded?

No. The board is drawn, saved and exported entirely in your browser.

Stays on your computer How this works

Free online whiteboard

A tiny whiteboard for diagrams and planning — drag shapes, connect them, all in your browser

Your work in progress is kept in this browser automatically, and Save stores it as a named board under Boards — nothing is uploaded. To keep a board anywhere else, download it as a JSON board file and open it here again later. Double-click a shape to type — long text wraps automatically. Highlight part of the text while editing to bold/italic/underline just that portion, or use the toolbar to style the whole shape. Drag to move; copy/paste with Ctrl+C / Ctrl+V. Select several at once by Ctrl-clicking or dragging a box over them (Ctrl+A selects all), then move or recolour them together. Click a connector line to recolour it or press Delete to disconnect.

About this online whiteboard

Drag shapes onto a board, connect them, label them, and export the result as PNG or SVG. Work in progress is kept in your browser as you go, and Save keeps named boards there too, so you can have several and come back to them.

Intended for the quick sketch you would otherwise do on paper — no sign-up, no team setup, no invitations. It is free to use, with no account and no upload limit, and it runs entirely in your browser: nothing is uploaded, and while the page stays open, a feature you have already used keeps working offline.

What you can do

An online whiteboard with boxes, ellipses, sticky notes, diamonds, triangles, parallelograms, hexagons, cylinders and text
Connect two shapes with an arrow that stays attached when they move
Drag and resize shapes, with alignment guides that snap to the shapes around them
Type into a shape, with wrapping text you can make bold, italic or underlined in part or whole, resize and align
Colour shapes and connector lines from a palette
Select several shapes to move or recolour together, and copy and paste them with Ctrl+C and Ctrl+V
Export the board as PNG or SVG
Save named boards in this browser and reopen them, with work in progress kept automatically
Download a JSON board file that opens here again, to keep a board or move it to another computer
Full-screen mode

How to sketch a diagram

Add shapes from the Shapes menu and drag them where you want them.
Use Connect to draw a line between two shapes; the connection follows them when they move.
Type into a shape to label it, and use the bold, italic, underline and text size controls to format it.
Save the board to come back to it, download it as a PNG or SVG, or download the board file to keep it somewhere else.

Questions

How is this different from the Diagram Toolkit?: This one you draw by dragging; that one you write as text. Use this for a quick sketch or a layout that has no regular structure, and Mermaid for anything that belongs in version control.
Where are my saved boards kept?: In your own browser's storage on this machine. That means they survive closing the tab, but they do not follow you to another computer or another browser, and clearing site data removes them. To keep a board safe, or move it to another computer, download it as a board file (JSON) from Boards and open it here again later.
Do the connectors stay attached when I move a shape?: Yes. Connect links two shapes rather than drawing a loose line, so the line follows them around.
Should I export PNG or SVG?: SVG if it is going into a document or might need resizing, since it stays sharp and keeps text as text. PNG for pasting into a chat or a slide.
Is anything uploaded?: No. The board is drawn, saved and exported entirely in your browser.