Internet & SIM cards on Koh Chang.

AIS Fibre is the default choice along Koh Chang's developed west-coast strip — White Sand Beach, Klong Prao, Kai Bae and Lonely Beach — where most guesthouses, villas and small resorts can get a line installed. Plans typically run roughly 500-1,000 baht a month for speeds from a few hundred Mbps up to gigabit tiers. As an island fed across shared mainland backhaul from Trat, installation can take longer than in a mainland city, and speeds can dip during the May-October monsoon low season.

True Online is the other major fibre provider on the west coast, often bundled with TrueVisions TV and a discount on a True mobile line. Coverage and pricing closely track AIS along the main beach road through White Sand Beach, Klong Prao and Kai Bae; Bang Bao's stilted fishing-village pier and the quieter Klong Son bay near the ferry piers see thinner availability.

3BB (now under the AIS/National Telecom umbrella) is the budget fibre option where it reaches, undercutting AIS and True on price for a no-frills connection. Availability is the patchiest of the three on Koh Chang, so always confirm a line actually reaches your specific bungalow or villa before signing a lease.

Fibre reaches the developed beach strip — White Sand Beach, Klong Prao, Kai Bae and Lonely Beach — comfortably, but a large majority of Koh Chang's mountainous interior sits inside Mu Ko Chang National Park and is effectively unconnected by fixed line. Bang Bao's pier village and the southern Salakphet area also see thinner fibre coverage than the main west coast. If a fast, dependable wired connection matters, favour White Sand Beach, Klong Prao or Kai Bae, and treat anywhere off the main coastal ring road as mobile-first.

Thailand has three main mobile networks: AIS (the largest, with the strongest coverage on islands, boats and remote roads), True (now merged with dtac, strong in built-up centres and heavily bundled), and the merged True/dtac network competing closely in developed areas. On Koh Chang, network choice genuinely matters — the island has no airport of its own, so most arrivals either fly into Trat and transfer by road to the ferry piers or drive the car ferry directly from Ao Thammachat/Centrepoint near Laem Ngop — and AIS carries the most consistent signal on that crossing and along the island's hillier interior roads. Along the main strip from White Sand Beach through Kai Bae, both AIS and True deliver workable 4G.

Prepaid (top-up) SIMs are the easy starting point: buy one over the counter with your passport, add credit, and pick a data package — no contract, no credit check. Postpaid (monthly bill) plans can be cheaper per gigabyte for heavy users and give a fixed number, but require more paperwork — typically a passport plus proof of address or a long-stay visa, and sometimes a deposit for foreigners. Most long-stayers on Koh Chang start on prepaid and only move to postpaid once settled with a lease and address on the island.

Tourist SIM packages — typically 8, 15 or 30 days of generous or unlimited data for a few hundred baht — are sold at Trat Airport and by vendors at the mainland ferry piers, since that's how most travellers reach the island. They're convenient for the first week while you settle in, but poor value across a multi-month stay. For a long stay, buy a standard prepaid SIM from an operator shop or convenience store on White Sand Beach or Klong Prao and attach a monthly data package, which works out cheaper than repeatedly renewing tourist bundles.

AIS and True both support eSIM on compatible phones, activated in-store by scanning a QR code — handy if your phone lacks a spare physical slot. Because Koh Chang has no airport, many arrivals fly into Trat or Bangkok and transfer overland to the ferry, so an international travel eSIM (Airalo, Holafly and similar) lets you land already connected for that transfer. For a longer stay, a local physical or eSIM plan from a Thai operator is cheaper. Confirm your phone model supports eSIM before relying on it.

Koh Chang doesn't have a dedicated coworking hub the way some larger Thai islands do; remote workers typically rely on laptop-friendly cafes along White Sand Beach and Klong Prao paired with a home fibre line as the mainstay connection. The standard setup is fibre plus a generous AIS mobile data package as backup — useful given the island's shared mainland backhaul can see slower speeds during storms in the May-October monsoon low season, when some businesses also reduce hours.

White Sand Beach, Klong Prao, Kai Bae and Lonely Beach have solid connectivity: 4G is fast and near-universal along the main coastal road, and fibre-to-the-villa comfortably handles video calls and uploads where it reaches. The picture changes toward the Mu Ko Chang National Park interior, Bang Bao and the southern Salakphet coast, where you may be on mobile-only coverage. Confirm the real speed at your specific address during a viewing rather than assuming coverage from a nearby area.

Topping up a prepaid SIM is straightforward: use the operator's app (myAIS, TrueiD), buy a top-up at any 7-Eleven or convenience store — most common on White Sand Beach and Klong Prao, fewer options further out — or dial the USSD code on your SIM starter pack. Once you have credit, activate a data package through the app or a short code. The apps also let you check your balance, buy add-ons and set auto-renew.

Most arrivals buy a SIM at Trat Airport before the transfer to the ferry piers, or at operator shops and convenience stores along White Sand Beach and Klong Prao once on the island — the best one-stop options for postpaid, eSIM activation and English-speaking help. Thai law requires SIM registration, so bring your passport; the shop registers it to you on the spot.

Expect roughly 500-1,000 baht a month for home fibre depending on speed and distance from the main beach strip, and 300-600 baht a month for a solid mobile data package. A basic prepaid starter SIM costs around 50-200 baht before data — broadly in line with pricing on Thailand's other Gulf-coast islands. All-in, a well-connected household on Koh Chang typically spends around 800-1,600 baht a month on internet and mobile combined.

What is the best home internet provider on Koh Chang?

AIS Fibre and True Online are the two main fibre providers on Koh Chang, with 3BB a value alternative where it reaches. Coverage is best along the developed west-coast strip — White Sand Beach, Klong Prao, Kai Bae and Lonely Beach — at roughly 500-1,000 baht a month. Much of the island's Mu Ko Chang National Park interior and the southern Bang Bao/Salakphet area have thinner or no fixed fibre, so confirm real availability with the landlord before you sign.

Which mobile network has the best coverage on Koh Chang?

AIS has the strongest and most consistent coverage on the island, including the hillier interior roads and the ferry crossing itself — a real factor given Koh Chang has no airport and most arrivals reach it via Trat Airport plus a road transfer, or the car ferry from Ao Thammachat/Centrepoint near Laem Ngop. True (now merged with dtac) is close behind along the main beach strip from White Sand Beach through Kai Bae.

Should I get a prepaid or postpaid SIM on Koh Chang?

Most long-stayers start with a prepaid (top-up) SIM, bought over the counter with just a passport and no contract, then add a monthly data package. Postpaid plans can be cheaper per gigabyte for heavy users but need more paperwork — proof of address or a long-stay visa, and sometimes a deposit for foreigners.

Is Koh Chang's internet reliable enough for remote work?

Along the main strip — White Sand Beach, Klong Prao, Kai Bae and Lonely Beach — yes: fibre and 4G comfortably handle video calls and uploads. There's no dedicated coworking hub on the island, so most remote workers pair a home fibre line with laptop-friendly cafes and a backup AIS mobile SIM, which matters more during the May-October monsoon low season when speeds can dip.

How much does internet and mobile cost per month on Koh Chang?

Budget roughly 500-1,000 baht a month for home fibre and 300-600 baht for a good mobile data package, with a basic prepaid starter SIM around 50-200 baht before data. A connected household typically spends about 800-1,600 baht a month combined — in line with pricing on Thailand's other Gulf-coast islands.