Onshape

Onshape is a fully cloud-native modeller: nothing to install, every document autosaves with a complete version history automatically, and several people can edit the same part at once the way they would a shared text document. It runs identically on Windows, macOS, Linux, Chromebooks and tablets because the modelling actually happens on Onshape's servers, not your machine.

The free plan is genuinely capable — professional-grade tools, not a crippled demo — but every document created on it is public by default, which is fine for practising on this archive's exercises but not for original commercial work you want to keep private. That distinction, more than any missing feature, is what pushes teams onto a paid plan.

Choose Onshape if you regularly switch computers, want to practise from a school or library machine with nothing installed, or like working on a design with someone else at the same time.

Compared with Fusion, the other cloud-connected option, Onshape has no local install and no offline mode at all — every document lives and computes on Onshape's servers — while Fusion is a locally-installed app that happens to sync to the cloud. Compared with the desktop parametric tools, Onshape's free plan is the most capable of any on this list, at the cost of every free document being public.