Stuck Between Thailand and Zanzibar, any suggestions?

Hey all, we are taking our honeymoon starting the first week of November and are stuck between Zanzibar and either Phucket or Krabi (undecided between those two thailand destinations).

Does anyone have any recommendations or experience with either destination to help our decision? Or even somewhere else we haven't thought of? Hotel/resort recommendations welcome as well!

We want a chill secluded getaway but with the ability to do some adventures or activities later in the honeymoon if we get bored of lounging and relaxing!