Thailand is the easiest eSIM market in Southeast Asia. Connectivity is good, the carriers are modern, and you'll have signal basically everywhere except the most remote parts of the southern islands. The challenge isn't coverage — it's figuring out which plan is actually priced fairly.
Check your phone first
iPhone XS (2018) or later: yes. Pixel 3 or later: yes. Galaxy S20 FE or later: generally yes, with the same mainland China exception as everywhere else (China-bought phones often have eSIM disabled).
One thing specific to Thailand: if you're going to be using local apps like LINE Pay or banking apps that send SMS verification, a data-only eSIM won't receive those texts. You'd need a voice+SMS plan for that. SimOptions has voice+SMS Thailand SIMs. Driftvoy is data-only.
The networks: AIS, True, and what happened to DTAC
Thailand has two relevant networks for travel eSIMs: AIS and True. DTAC merged into True in 2023, so when you see "DTAC coverage," that's now True's infrastructure.
AIS has the largest number of cell towers in Thailand and the broadest coverage in rural areas and smaller islands. True is strong in cities and has good coverage across the major tourist areas.
Driftvoy uses AIS and True. Saily uses AIS. Nomad uses True/DTAC infrastructure. Airalo uses AIS + True. Coverage-wise, they're all in the same range for where most travelers actually go.
Where coverage genuinely drops: Koh Lipe (southernmost, near Malaysian border), parts of the Surin and Similan Islands, very remote northern villages. Every eSIM provider has the same limitation there — it's a carrier infrastructure issue, not a provider issue. If you're island-hopping to remote spots, download offline maps before you leave the mainland.
What plans actually exist and what they cost
1 GB / 7 days: Saily is around $2.69. Driftvoy is $3.99. Airalo is ~$4.50. Good for very short trips or as a backup while mostly on hotel WiFi.
3 GB / 30 days: Saily ~$5.99, Driftvoy $6.99, Airalo $8.00. Saily is the cheapest here. On a 2-week Thailand trip with hotel WiFi each evening, 3 GB is tight but possible.
5 GB / 30 days: Driftvoy $7.99. Comfortable for most travelers doing 10–14 days.
10 GB / 30 days: Driftvoy $9.99, Nomad ~$10.00, Airalo ~$11.00. This is where most people land for a 2-week trip with moderate data use (maps, messaging, some Instagram, occasional Zoom).
50 GB / 10 days (Driftvoy Launch Deal): $9.99 for the first 100 orders, $14.99 after. Nomad has a 50 GB / 10 days at around $10–12. This SKU is unusual — most providers don't offer it. It's for travelers doing a 1–2 week trip who need heavy data: hotspotting a laptop, video calls, live streaming.
Holafly unlimited: Around $27 for 10 days. Throttles after a daily data threshold. Same caveat as Japan — works fine for messaging and light browsing, frustrating if you're trying to actually work or stream.
What I'd actually buy depending on the trip
A week in Bangkok + Phuket, mostly social media and maps: 5 GB / 30 days. Any provider.
Two weeks including islands, occasional Zoom calls: 10 GB / 30 days. Driftvoy and Nomad are competitive here — roughly the same price.
Short trip (10 days or less) with heavy data or laptop work: 50 GB / 10 days. Driftvoy's Launch Deal or Nomad's equivalent.
Month+ stay: 20 GB / 30 days, or buy a local SIM card at the airport. Local SIM cards in Thailand are extremely cheap — AIS and True both sell tourist SIMs at Suvarnabhumi for under $10. For stays over 3 weeks, a local SIM often wins on price.
Suvarnabhumi airport: what actually happens when you land
You land, turn off airplane mode, and the eSIM connects automatically. AIS and True both have strong coverage throughout the terminal. There's no setup step. You're online before you reach baggage claim.
The main mistake people make: they try to install the eSIM at the airport on airport WiFi instead of at home on a proper connection. Install at home. The QR code comes by email, the installation takes 2 minutes, and you don't want to troubleshoot it in a crowded terminal after a long flight.
A note on pricing honesty
Nomad is genuinely competitive on Thailand. Their 50 GB / 10 days SKU matches or beats most providers, and their 10 GB / 30 days at ~$10 is at parity with ours. If you've used Nomad before and it worked for you, there's no compelling reason to switch to a new brand for Thailand.
Where Driftvoy's argument holds up: same-eSIM top-up (you don't reinstall when you add data), and a money-back guarantee if the eSIM isn't delivered or fails to activate. Whether those features matter to you depends on your travel style.
Islands coverage: the real answer
Phuket: Full coverage, no issues. Major resort areas have 4G everywhere.
Koh Samui, Koh Phangan, Koh Tao: Good coverage on both AIS and True. Koh Tao is the smallest of the three and signal varies more, but it's usable.
Koh Phi Phi: Main areas fine. More remote beaches are spotty.
Koh Lipe: AIS has some coverage, but it's intermittent. Download offline maps.
Similan Islands, Surin Islands: Day trips only — signal is minimal. Not worth buying extra data for.
Driftvoy is launching in September 2026 with Thailand eSIM plans from $3.99. Join the waitlist for 10% off your first plan.