By shared minivan (most popular)
Shared minivans depart daily from pickup points across Ao Nang, Krabi Town and Ao Nam Mao, taking roughly 2.5-4 hours to cover the ~150-160km route, with fares typically 350-450 THB per person. This is the standard way most independent travellers make the trip — book a day or two ahead in high season, and note that luggage space is limited, so a large suitcase may need its own paid seat.
By private taxi
A private car or taxi covers the same route in roughly 2-3 hours, for a noticeably higher fare (roughly 2,500-3,500 THB for the vehicle). Worth considering for families or groups splitting the cost, or anyone wanting a direct run without other passengers' stops.
Avoid the long way round
Some minivan routings detour via Khao Lak, adding significant time to the trip. When booking, ask specifically for a direct Krabi-to-Khao Sok service rather than one that loops via the Phang Nga coast.
What's at the other end
Khao Sok is best known for Cheow Lan Lake's floating bungalows, ancient rainforest hiking, and wildlife spotting — a genuinely different landscape from Krabi's limestone coastline, and a popular 1-2 night add-on for travellers heading further north afterward toward Surat Thani or Khao Lak.