Uploading of projects and theses I’m an undergraduate currently working on a project with my supervisor. As far as I know, my supervisor is generally reluctant to publish (that includes the university database). I suspect this will also be the case for the project I’m working on. Is it legal if I upload the final version on say ResearchGate? I want to communicate with others about what I have done and since it is likely that my Bachelor’s thesis will be done under said supervisor, I would like to know what options I have. I can only think of describing the project/thesis in detail as an alternative if I want to list said project/thesis.
None of this would be illegal, at all likelyhood (but I am not a laywer).
The more important question is whether it is ethical or not.
With regard to theses (i.e., bachelor, master thesis, also PhD thesis), I don't see any issue in posting the thesis somewhere public. (Indeed, PhD thesis usually must be published.) After all, your thesis is your work (certainly this is the formal point of view), and it is up to you what you do with your work.
On the other hand, if you have a supervisor who wants to publish results from the thesis as part of a journal article, it might be better not not publish the thesis before that, such as to protect your ideas until the paper is out. However, this is more about being smart than about being ethical. Also, as far as I see there is no such issue involved here.
Note that the situation is different for results which are not part of the thesis, and which is not solely your work: In that case, you cannot publish them without consent of your coauthors. (Again, this is not about being illegal, but about research and publication ethics.)
Finally, even if it is fine to post your thesis, a bachelor thesis in practice often does involve contributions from the supervisor, so it is probably smart to ask them for permission. As has been pointed out, they might well be happy to showcase good students.  And last, since your supervisor does not seem to care much about publishing, they should not mind those ideas being publicly available (unlike when they would like to use towards for a publication).