Koh Phi Phi or Langkawi?

Phi Phi has the more striking water: turquoise, very clear and enclosed by cliffs, with Long Beach looking across to Phi Phi Leh and the soft sand of Laem Tong in the north. Boat trips to Bamboo Island and the coves of Phi Phi Leh are the high point, although Loh Dalum turns shallow at low tide and fills with day-trippers.

Langkawi's beaches are longer and easier rather than spectacular. Pantai Cenang is a wide sweep of pale sand with sunset views, and Tanjung Rhu and Datai Bay are quieter. Its sea is pleasant rather than glass-clear, so snorkellers take a boat to the marine park islands.

Neither island is a place to travel for food, but Langkawi eats a little better. Its pasar malam night markets move from village to village with satay, grilled fish and kuih, and seafood places along the coast sell the catch by weight. Kuah's canteens add roti canai and noodle soups.

On Phi Phi, eating mostly means the Tonsai lanes, where much of the cooking is toned down for backpackers. The highlights are simple: banana roti from a cart and seafood grilled on the beach in the evening.

Phi Phi has almost nothing to set out for: a small tsunami memorial, and a look at the cliff entrance of Viking Cave from a passing boat. Langkawi can fill a morning. It has Mahsuri's tomb in its heritage village of traditional Malay houses, the Al-Hana mosque on the Kuah waterfront, the story of rice growing at Laman Padi and the state gifts in the Galeria Perdana. On both islands, the sights are something for a rainy morning, not a reason to choose one over the other.

Phi Phi is the party island of the two. Every night the Loh Dalum bars lay mats on the sand, put on fire dancing and play loud music until the early hours, and the village adds reggae bars and Muay Thai bouts staged for visitors. It is one scene repeated rather than a range, but it is a real night out.

Langkawi's evenings are mild by comparison: bean bags and fire-twirling on Pantai Cenang, cheap duty-free drinks, and an island that is mostly dark before midnight.

Both are limestone landscapes, and Phi Phi edges ahead on the sea. You get kayaking into Pileh Lagoon, soft-coral walls at Bida Nok and Bida Nai, blacktip reef sharks at Shark Point and bolted climbing cliffs near Tonsai. The island is small, though, and its reefs show wear from heavy boat traffic.

Langkawi's nature is on land and among the mangroves: boat trips through the Kilim channels with eagles overhead, the cable car over the old rainforest of the Machinchang range, the Seven Wells waterfall and hornbills on Gunung Raya. It has more variety, and Phi Phi has the better water.

Both islands are mostly about boat tours to nearby bays, but Phi Phi sits better placed on the Andaman ferry routes. Koh Lanta is about an hour away and Railay's cliff-backed peninsula a little further, and Phuket Town's shophouses can be done in one long day.

From Langkawi, the realistic outing is Koh Lipe across the Thai border. The mainland trip to Alor Setar is long for what you get there.

Langkawi is the more natural family island. It has shallow, warm water on the Cenang strip and resorts with pools and kids' clubs. Underwater World, the sky bridge and the eagle-feeding boat trips fill several days, although midday heat and the need for a car are drawbacks.

Phi Phi can work if you base yourselves at Laem Tong, where the water is calm and children love the longtail boats. The village is loud and cramped, the hill paths are steep and unlit, nothing is built for children and medical care is basic.

These are two opposite set-ups. Phi Phi has no cars at all. The village and Loh Dalum are a short walk apart, but everything else means a longtail or a rough hill path, and simply reaching the island takes a ferry of up to two hours.

Langkawi is easier to cover. It is about 25km across, with good, quiet roads, cheap car and scooter hire and ride-hailing apps, and the airport is next to Pantai Cenang. The trade-off is that you can only really walk along the Cenang and Tengah strip.

On Phi Phi, shopping means the village lanes of beachwear, sarongs, sunscreen and snorkel gear, so bring anything else with you from the mainland.

Langkawi is a duty-free island from end to end. The big complexes in Kuah and along Pantai Cenang sell chocolate, alcohol, cosmetics and kitchenware, and the stalls and night markets add batik sarongs and pearls. That is enough for an afternoon of stocking up, though there are no fashion streets or crafts to go looking for.

Langkawi is noticeably cheaper day to day. Night-market meals, fuel and car hire cost little, mid-range hotels around Pantai Cenang stay modest even in the dry season, and duty-free status keeps beer and wine cheap. Only the luxury rainforest resorts charge international rates.

Phi Phi costs more than most of Thailand, because everything comes in by boat. Dry-season rooms are dear, longtails and drinks add up, and there are entry fees for the island and the marine park.

On both islands, live entertainment amounts to fire dancing on the beach and cover acts in bars. The only difference is that some Langkawi resorts stage Malay cultural shows over dinner, while Phi Phi's shows are part of a party night.

Langkawi is the more restful island overall. Traffic is light and evenings are quiet, and the spas in the northwest rainforest and along Tanjung Rhu draw on Malay herbal traditions, with cheap reflexology shops in Cenang besides.

On Phi Phi, how relaxing your stay feels depends on where you sleep. The hammocks and resort spas of Laem Tong are calm, but Tonsai's music carries late into the night.