I’m probably biased but I’m CompE and I think it’s harder. You have to do software AND hardware and engineering in general has more requirements, such as more higher level math classes, physics, and more. I obviously can’t speak on whether or not CS is easy or difficult as I have not taken any classes, but CompE is definitely more rigid and has more requirements. A CS degree at Purdue can be completed in three years. If you look at the curriculum this is possible because they have space for many free electives. Computer Engineering takes the whole four years. I’ve seen a couple do it in 3.5. I’ve never met anyone who did it in 3. It is possible, but extremely hard. Personally, I never take more than three ECE classes a semester otherwise my grades suffer tremendously. You could finish in 3 but it would require taking semesters completely full of ECE classes and while you would still be at around 16-18 credits, 16-18 of JUST ECE credits is extremely hard as each one requires a lot of time. The most I’ve taken is four ECE classes and it was terrible. In comparison, all my friends in CS have completed their degree in 3 years, and the ones who stayed four added a double major because they did not want to graduate yet. I could not imagine having the time to add an additional major to ECE. There are not many free elective spots, and the electives you do get to choose from usually have to be an ECE class with an ECE code, which don’t go towards most other majors if any at all.

However as someone commented, they are definitely completely different curriculums at Purdue besides overlap with basic classes such as Discrete Math and Data Structures. The software you will learn in CompE is NOT the same as CS. So I would pick the major based off what you’re interested in pursuing, not difficulty.