Diagram Editor & Flowchart Maker

The editor runs entirely in your browser tab. Shapes, connectors, the undo history and the clipboard are held in the tab's memory, and drawing, exporting and creating a share link all happen on your device, so the diagram never travels over the network. No part of the diagram is written to local storage, cookies or IndexedDB. The site keeps only its list of recent tools and, if you create a share link, a note that you shared one, never the diagram itself.

That also means the diagram lasts only as long as the tab. You can open another page of this site and come back in the same tab without losing it, but closing or reloading the tab clears it, and the browser asks first when there are unsaved changes. Save downloads a file you can keep. On phones, the browser may reload a tab while you are in another app, so save often.

Save downloads a plain JSON file named after the diagram title, such as order-processing-flow.diagram.json. It lists every shape with its kind, position, size, label and style, and every connector with the two shapes and sides it joins, its routing, label and style. Style fields that match the defaults are left out, so files stay small and easy to read in a diff.

Open reads the file back, and so does dropping it onto the editor. Every value is checked as it loads: shapes of an unknown kind and connectors with a missing end are skipped, colours must be six-digit hex codes such as #2563eb, and sizes, font sizes and line widths are kept within their limits. Labels are always treated as plain text. Files up to 20 MB open, with up to 1,000 shapes and 2,000 connectors.

Export builds an SVG from the diagram data rather than taking a screenshot. Each shape outline, connector, arrowhead and label becomes an SVG element, with labels as real text, and the image covers the diagram plus a small margin. You can export the whole diagram, or only the selected shapes with the connectors between them.

For a PNG, the browser draws that SVG onto a canvas at 1x, 2x, 3x or 4x, on a white or transparent background. Browsers limit how big a canvas can be, so a very large diagram at a high scale is scaled down to fit. Labels use the system's sans-serif font, the same one the canvas shows, so the PNG matches the screen.

Share writes the diagram in the same format as the saved file, compresses it and places it after the # in the link. Browsers never send that part of an address to a web server, so the diagram travels only inside the link you send. A link holds about 100,000 characters of diagram data; for anything larger, send the saved file.

With a password, the diagram is encrypted in your browser with AES-256-GCM before it goes into the link, using a key derived from the password with 600,000 rounds of PBKDF2. An expiry of 1 hour to 30 days can be added, and it is checked by the browser that opens the link. There is no server, so a link cannot be revoked once it is sent.

Shortcuts work only while focus is inside the editor, so keys pressed elsewhere on the page keep their normal meaning, and text fields keep their own keys. Click the canvas or move to it with Tab, then use Tab and Shift+Tab to select each shape and connector in turn; after the last item, Tab moves on to the rest of the page. Arrow keys move the selection by 1 px (10 px with Shift), Enter or F2 edits the label, and Delete removes the selection with its connectors.

Shapes can be added, selected, edited, moved, styled and deleted without a mouse: a shape tile adds its shape when you press Enter, and the format panel is reached with Tab. Drawing a connector and moving a connector end still need a mouse, pen or touch. Zoom and fit skip their animation when your system asks for reduced motion, and ? opens the full list of shortcuts.