Will taking 4 courses in a semester affect my chances of getting into grad school? I am currently a Computer Science/Mathematics student going into my 3rd year of a 4 year program. I spent a year in a different program at a different university and was able to transfer those credits, but I was not able to take courses in a way that I could graduate quicker. However, these credits do allow me to take 4 courses for some semesters instead of the usual course load of 5. Would taking advantage of this reduced course load to work on personal projects affect my chances of pursuing graduate studies in Computer Science?

Aside: I have good/strong grades so far.
I don't think it should be a problem, provided that you are taking some challenging Math/CS classes among your 4 classes.  If it looks like you're trying to skirt by with the bare minimum difficulty of classes, then taking a couple fewer classes could reinforce that negative narrative.  But as long as it looks like you're taking a challenging course load and doing well, I don't know that people will even notice the 4 vs. 5 issue (since there are schools where 4 courses is a normal load).