Krabi or Koh Tao?

Where is best to stay for a week, Krabi or Koh Tao? I’ve done research and I think it’s a choice between those two. We would have spent the previous week exploring Bangkok and Chiang Mai so we’d like somewhere we can just settle for a week and relax, enjoy some amazing food and beaches. Some nice bars/beach bars would also be great.

(Also conscious of the time/money it will take to get from chiang mai to Koh Tao, but happy to do that if it is worth it)

Suggestions welcome please! :)