Web and Desktop Differences

The editor on the website is MatterCAD itself: the same shapes, operations, Properties panel and 3D view as MatterCAD on your computer. A web page can’t reach your computer’s files or other programs, though, so a few things work differently.

Your Designs and Files

  • Save keeps the design in your online library, not in a file on your computer. Save As asks only for a name: the copy goes in the folder you opened the design from when you may add to it, otherwise in My Designs. See Saving on the Web.
  • Export and the page’s Download button are how you get a file on your computer. Your browser downloads it.
  • Add to Bed has no Computer folder. To bring in a file from your computer, use Add System File to Bed (your browser asks you to pick the file) or drag the file onto the 3D view. See Adding Parts on the Web.
  • Unsaved changes are kept as a copy in your browser, which holds designs up to about 3.5 MB. MatterCAD on your computer offers to recover unsaved work when it starts instead (Saving and Exporting).

The Window and Menus

  • Each design has its own page. There are no tabs, no Library or Help tab, and no status bar along the bottom.
  • The toolbar’s MatterCAD menu holds New Design, Interface Tour, Help and Settings. Open System File, Open Recent, Check For Update, Community and About MatterCAD are only in MatterCAD on your computer.
  • There is no Check For Update: the website runs the version of MatterCAD it serves. Reload the page to get a newer version once the website has one.
  • Settings has only Number format and Depth Peeling Layers. The colors follow the light or dark theme you chose on the website (The MatterCAD Menu).
  • The Bed menu has no Reload.
  • A selected part has no Help button and no Help Docs menu row. Open Help from the MatterCAD menu instead. The first time you open it, its articles take a moment to load (Help).
  • There is no Open With in a part’s right-click menu, and no menu item that shows a file in your computer’s file manager.
  • Save as Tool, for node graphs, is only in MatterCAD on your computer.

AI

  • The AI tab goes through the website and never uses AI keys of your own.
  • Outside AI tools such as Claude Code, Codex and Claude Desktop connect only to MatterCAD on your computer, not to the website’s editor (Using AI Assistants).

Variable Sheets

A sheet’s importdata() can’t read a file or a web address in a browser. Instead of a value, the cell shows: “Error: importdata cannot read files or web addresses in the browser. To import data, open this design in the MatterCAD desktop app.” See importdata.

Keyboard

  • Click in MatterCAD’s part of the page before you use keys, so they go to MatterCAD and not to the web page.
  • While you edit, Ctrl+S and Ctrl+Shift+S (⌘S and ⌘⇧S on a Mac) run MatterCAD’s Save and Save As, not your browser’s “save page”. While you only preview the design, they are your browser’s.

The Browser You Need

MatterCAD on the website needs a browser with WebGPU, such as a current Chrome, Edge or Safari. Without it, the page shows a message and a Download file button instead of the design (What You Need).