Choosing between Phuket and Koh Samui in 2026 depends heavily on your travel style and the timing of your trip. Phuket, Thailand's largest island, is better for those seeking variety, high-energy nightlife (especially in Patong), and easy accessibility via its international airport and land bridge. It offers a massive range of accommodations from budget hostels to ultra-luxury clifftop villas. Conversely, Koh Samui provides a more "island" feel with its strict building code—no structure can be taller than a coconut tree. It is better for travelers seeking a more relaxed, upscale atmosphere with world-class beach clubs and clearer, calmer waters. Weather is a crucial tie-breaker: Phuket is best from November to April, while Koh Samui shines from February to August. If you want endless activities and day trips to places like Phang Nga Bay, choose Phuket; if you want a romantic, boutique-heavy escape with a slower pace of life, Koh Samui is the superior choice.