Since it’s a small, but fascinating, island in Kedah Province of Malaysia, transportation is not a big issue. There are mainly 3 options, listed from expensive to cheap:
You can ask for your hotel’s shuttle service. This will be the most expensive option. One-way trip will cost around 80 MYR (19 USD) for Kuah.
You may use taxi (without meter) mostly fixed price. But do not forget to negotiate. One-way trip will cost around 35 MYR (8 USD) to Kuah.
If you have the internet in your mobile, you may use applications Uber and Grab. There are not too much Grab Driver in Langkawi, Uber is more common. One-way trip will cost around 20 MYR (4.5 USD) to Kuah.
Car Rental in Langkawi Airport
If you are planning to explore all the island, I advise you to rent a car from Airport. But do not forget, Malaysia has left-hand traffic i.e. Malaysia drives on the left. This will cost you 120MYR (28 USD)/day approximately.