Hello !How can I use the same file, on two or more computers at the same time? Just like we do with the shared mode of excel online, where all users make changes live.

Not exactly like Excel but you might be able to use partial open - https://www.cadforum.cz/en/open-just-a-part-of-a-dwg-drawing-layers-views-tip11868 or the online version of AutoCAD https://www.cadforum.cz/en/concurrent-editing-of-a-dwg-file-from-two-remote-pcs-tip8566

I accessed CAD 360 (which is now Autocad mobile) and it does not unify the changes made by users.When the two computers save the file, the app doesn't merge the changes, but gives the option to create a copy, or use the PC version that saved it first.Do you know of any way for two people to save the file at the same time, and the CAD merge the changes?

"CAD" is too generic a term.  If you mean AutoCAD specifically, I don't think it can do that.  Revit can have more than one person working in the same file, if that's a possibility for you, though it wouldn't allow saving at the same time.  But it will merge each person's changes into a central file, and others working in it can synchronize to get others' changes to show in their program.Kent Cooper2022-09-12 19:22:00

Hello everybody, I don't know if the word "use the same file, on two or more computers at the same time" is OK. I would more use the word "give the hand on one file" to an other person through an internet conversation like with "TEAM" with wich you can talk on the "telephone", show and "share" documents, etc...In any case, I find a "multiple access" dangerous but an "alternative" property more safe.There are softwares like Solidworks in wich the file belongs to its owner an he can eventually "give access in working and saving" an not only "reading".
philippe JOSEPH2022-09-13 07:39:48