This route combines a capital, a northern city and an Andaman coast base. Keep it only if the trip is long enough to absorb two major transfers.
Bangkok needs time beyond the arrival night. Chiang Mai rewards at least two full days in the city and surrounding area. In Krabi, choose Krabi Town for local life, Ao Nang for easy tour logistics or Railay for a boat-dependent stay.
Chiang Mai–Krabi flights are not equally convenient every day. If the useful direct service does not fit, a Bangkok connection can turn the move into a full travel day.
TAT highlights Krabi’s beaches, islands, kayaking and climbing, but sea conditions decide whether boat days operate comfortably. During the southwest monsoon, ferry and excursion plans require current checks.
Also check Chiang Mai PM2.5 before committing to a northern stay. If either condition is poor, changing the order may be more useful than adding another destination.