Direct flights
Scoot operates the only non-stop service between Singapore Changi Airport (SIN) and Krabi International Airport (KBV), with flight time running around 1 hour 45 minutes to 2 hours depending on conditions. Flights operate several times a week rather than daily, so check the schedule against your travel dates rather than assuming daily availability.
Connecting flights
If Scoot's direct schedule doesn't line up with your dates, connecting options via Kuala Lumpur or Bangkok are available through AirAsia, Singapore Airlines and other carriers — these typically take 5+ hours total once the layover is included, meaningfully longer than the direct route.
Booking tip
As a single-daily (or less) direct route, seats on the non-stop Scoot service can sell out or price up during Krabi's December-February high season. Booking several weeks ahead generally secures better fares than last-minute booking.
Time difference
Krabi is one hour behind Singapore (Thailand: UTC+7, Singapore: UTC+8) — worth factoring in when booking early or late flights.