Is PMI ACP harder than PMP?

No, ACP® is not harder than PMP®. The PMI®-ACP exam is generally considered easier than the PMP® exam, especially if you have taken the PMP® already. You get about 1.

5 minutes per question in the PMI®-ACP, which is more time than for the PMP® questions. Preparing for the PMI-ACP® requires several weeks of study, but it is often seen as less demanding than preparing for the PMP®.