No account needed; sign-in only unlocks cloud save
Pasting, rendering, exporting and the auto-saved copy on this device never need an account, and never will. Sign-in only comes up when you click “Save” or the diagram name in the editor's top bar (on phones: “Cloud save” in the “Download” panel). It exists to store diagrams on the server so you can open them elsewhere. Until you click it, the page sends no diagram content to the server.
How to sign in
The two sites offer different methods: diagramate.com uses email and Google, diagramate.cn uses a phone number and WeChat.
- Email code: enter your address, receive a 6-digit code by email and type it in within 10 minutes. One email per address per 60 seconds, at most 10 a day; after 5 wrong attempts you need a new code.
- Google (diagramate.com): click “Continue with Google”, pick an account on Google's page and you're sent back to the editor. A Google account and an email-code sign-in with the same address are the same Diagramate account.
- Phone code (diagramate.cn): enter your number and receive a 6-digit code by text, valid for 10 minutes. One text per number per 60 seconds, at most 5 a day.
- WeChat (diagramate.cn): scan the QR code on a desktop, or tap to authorize when the page is open inside WeChat.
- Password: once you set one in your account settings, “phone or email + password” signs you in without waiting for a code.
You stay signed in on this browser for 30 days. “Sign out” only signs out the current device.
The free limit and what is stored
The free tier holds 3 diagrams; Pro holds 1,000. Each one stores the Mermaid code, the theme you had selected, the name you gave it, and the last 20 versions (each “Save new version” adds one). Exported PNG / SVG / PDF / Word / PowerPoint files are never uploaded; export always happens in your browser.
Deleting a diagram frees its slot immediately.
From October 2026 the free tier holds 3 diagrams instead of 10. If you saved more before that, nothing is deleted: you can still open, rename and save new versions of every one; you just need to get below 3 (or upgrade to Pro) before creating a new one.
One diagram's code can be up to 50,000 characters, the same as the rendering limit; anything longer would not render anyway, and the cloud dialog tells you so. Export a file to keep it on your device.
Saving, opening, other devices
- Save the current diagram to the cloud: click “Save” in the top bar (or press ⌘S / Ctrl+S). The first save asks for a name; from then on the top bar shows that name and “Saved”. When the content changes it turns to “Unsaved”; click “Save” or press ⌘S / Ctrl+S again to add a new version without opening the dialog.
- Open: click the diagram name in the top-left corner to open Cloud save, which lists your most recently saved diagrams; click one to open it, and the editor's content and theme are replaced. If the current content isn't saved yet, you're asked whether to save first or open anyway.
- Save as new diagram: stores the current content as a separate diagram without touching the original.
- Another device: sign in with the same account and the same diagrams are there.
The My diagrams page: open, rename, delete, version history
All your cloud diagrams are on the My diagrams page (from the account menu, the account page, or “All my diagrams” in Cloud save; the address is /diagrams):
- Open: goes back to the editor with that diagram. If the editor has unsaved content, you're asked the same question: save first, or open anyway.
- Rename and Delete: deleting frees the slot immediately; if that diagram is open in the editor, the next save creates a new diagram.
- History (Pro): each diagram keeps its versions from the last 30 days. “Restore this version” stores that version as the newest one and opens it in the editor.
- With more than 5 diagrams a search box appears to filter by name.
When two devices both changed a diagram
If the cloud already has a newer version when you save (for example, you saved from another device), you'll see “There is a newer version in the cloud” with two choices:
- Overwrite: stores this device's content as the newest version. The previous version stays in the history; nothing is lost.
- Use the cloud version: drops this device's changes and loads the cloud version into the editor.
First sign-in: import this device's diagrams
The first time you sign in, if this browser has auto-saved diagrams (one for the editor, one for the mind map page), you're asked once whether to save them to the cloud. After importing, the diagram in the editor is linked to its cloud copy, so later saves add versions. “Not now” stops the prompt; you can always use “Save the current diagram to the cloud” by hand.
Privacy
- Not signed in: your diagram is never uploaded (the one exception is described in AI fix, AI tidy and AI edit: clicking an AI button sends the code once, and it isn't stored).
- Signed in: only when you click save does that diagram's code, theme and name go to the server, and you can delete it on the My diagrams page at any time.
- The server stores no plain-text codes; sign-in sessions are stored as hashes only.
Share links (/editor#pako:…) are unrelated to cloud save: what's in the link never passes through a server.