"Crystal-clear" is ungradable, and as such is much stronger than "clear-cut", which is gradable. I would also suggest that "crystal-clear" is a metaphor referring to something that can be seen or heard (such as written or spoken instructions), whereas "clear-cut" is a description that is independent of our senses.

I agree with Phil's answer.

'clear-cut' is usually used for choices and decisions. It means that there is an obvious choice. 'crystal-clear' usually refers to an explanation of something, or a communication of some type. They aren't usually interchangeable. He gave a crystal-clear explanation. (not 'clear-cut') Your meaning is crystal-clear to me. (not 'clear-cut') There were three candidates for the job. It was a clear-cut decision to offer it to the first of them. (someone could say 'crystal-clear' here but it would be awkward) 'clear-cut' can also be a noun or verb referring to land where the forest has been completely removed. The trail crosses a region that was clear-cut in the '80s.

These are very similar phrases. If the situation involves seeing something, then I would use "crystal clear". Examples; Now that you have shown me how you want the flower arrangements to be made, I have a crystal-clear idea of how to make them. The company was suffering financially during the pandemic and they needed to have fewer employees. It was a clear-cut decision to lay-off ten employees. I think "clear-cut" may be used more often in sad situations.

Hi Yasuke. There is no difference, really, when you're speaking figuratively. When speaking literally, of course, there is great difference. I assume you wanted to know the literal difference?