the best tool for you design diagram which there are as below:

  1. is an open source technology stack for building diagramming applications, and the world’s most widely used browser-based end-user diagramming software.
    For me, I recommend you to use this tool because It’s easy export and share to our drive.

  2.  Lucidchart
    Lucidchart is the intelligent diagramming application that brings teams together to make better decisions and build the future.

  3. Excalidraw
    Excalidraw is a whiteboard tool that lets you easily sketch .

  4.  tldraw
    tldraw is a tiny little drawing app.

    Plan, visualize, and present better results — all in EdrawMax. Get started easily with the Microsoft-like interface, drag and drop feature, and professional template resources. With 280 types of diagram solutions, you and your team can use EdrawMax for every stage of your workflow.

  6. Miro
    Miro Lite is a free-to-use, easy-to-share online whiteboard.

  7. CloudSkew
    CloudSkew is an online diagram & flowchart editor.