Will I lose my diagrams if I close the tab?

No. Diagrams are written to this browser's local storage as you work and are there when you come back. You lose them by clearing site data, using a private window, or switching browser or machine — which is why saving a .diagram.json file to your disk is worth doing.

Can I open my diagram on another computer?

Save it to disk with ⌘/Ctrl + S, move the .diagram.json file across, and open it there with ⌘/Ctrl + O. Nothing syncs on its own, because nothing is uploaded.

Does it work offline?

Yes. Diagrams are drawn and rendered in your browser, and the icon set is bundled rather than fetched, so an open tab keeps working without a connection.

Saving and sharing

Saving your work

Diagrams live in your browser, not on a server. Here is how storage works, and how to save an editable .diagram.json file you own and can reopen any time.

Where your diagrams live

Diagrams are not saved on a server — there is no server to save them to. Your work is held in this browser's local storage, and it is written there as you draw, so a reload or a closed tab loses nothing.

What that does mean is that the following lose your diagrams, because they clear or bypass that storage:

Clearing site data or browsing history for this site.
A private or incognito window, once you close it.
Switching to a different browser, or a different machine.
Some “clean up storage” tools and aggressive privacy extensions.

Saving a file you own

So once a diagram matters, save it to your disk. Export → Save to disk, or ⌘/Ctrl + S, writes a .diagram.json file that belongs to you and can be backed up like any other document.

1Press ⌘/Ctrl + S to save the diagram you are on, or ⇧ + ⌘/Ctrl + S to save every diagram in the project as one file.
2Keep the .diagram.json file wherever you keep your work — a repo, a shared drive, a backup.
3To pick it up again, press ⌘/Ctrl + O, or the arrow button beside New, and choose the file.
4It opens exactly as you left it, fully editable.

A PNG or an SVG cannot be reopened for editing — they are pictures. The .diagram.json file is the editable one. Export both: the picture for the document, the file for next month.

Projects

Diagrams are grouped into projects — a label a diagram carries, so that everything for one client or one system can be listed, saved to disk and cleared out as a unit. A diagram belongs to exactly one project, and can be moved between them from the folder button on its row in the sidebar.

The sidebar footer shows how many diagrams the project holds and how much browser storage they are using, so you can see when it is time to move something to disk.

Frequently asked

Will I lose my diagrams if I close the tab?: No. Diagrams are written to this browser's local storage as you work and are there when you come back. You lose them by clearing site data, using a private window, or switching browser or machine — which is why saving a .diagram.json file to your disk is worth doing.
Can I open my diagram on another computer?: Save it to disk with ⌘/Ctrl + S, move the .diagram.json file across, and open it there with ⌘/Ctrl + O. Nothing syncs on its own, because nothing is uploaded.
Does it work offline?: Yes. Diagrams are drawn and rendered in your browser, and the icon set is bundled rather than fetched, so an open tab keeps working without a connection.

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