In July, Microsoft plans to make this lightweight Visio web app available to Microsoft 365 Business, Office 365 E1/E3/E5, F3, A1, A3, and A5 users. (Specific plans and licensing details are in ...

Diagrams are automatically saved into OneDrive by default in the Documents folder, but you can move them individually and export as an image, PDF or HTML code for embedding the diagram on a web page).