I live on Koh Phangan, and the question I get asked more than almost any other is some version of “how do I get internet sorted when I land?”
It is a fair thing to worry about. The moment you walk out of the airport in Bangkok you want a map, a Grab, and a way to message whoever is picking you up, and none of that works if your phone is still hunting for your home network at roaming prices. So here is how connectivity actually works in Thailand, written by someone who deals with it every day rather than someone who flew in for a week and wrote a listicle.
There are three real options: a travel eSIM, a local SIM card, and a pocket Wi-Fi device. Most people overthink it. Let me break down who each one is actually for.
The quick version
If you are here for a normal trip and you have a fairly recent phone, get a travel eSIM before you fly. Sorted before you land.
If you are staying a long time, or you need a local Thai number for things like Grab and food delivery, get a local SIM once you arrive.
If you are travelling as a group and want one connection for several devices, or your phone is too old to take an eSIM, a pocket Wi-Fi can make sense.
That is the whole decision. The rest is detail.
Travel eSIM: the easy default
An eSIM is just a SIM built into your phone that you activate with a QR code instead of a physical card. You buy it online, install it before you leave home, and it switches on the moment you land. No kiosk, no queue, no handing your passport across a counter while a line builds up behind you.
That last part is the real selling point in Thailand. A physical tourist SIM has to be registered to your passport, which means ten or fifteen minutes at a desk after a long flight. An eSIM from an international provider skips all of that. You land, you have signal, you walk to your taxi.
I usually point people to Holafly for this. It runs unlimited data, it lets you share the connection as a hotspot, and the support actually answers when something goes wrong. There are other good ones, but that is the one I have had the least trouble with.
Two honest caveats so you are not caught out. First, most “unlimited” plans in this part of the world have a fair use limit, usually somewhere around 2.5 GB a day at full speed before they slow you down until the next day. That is fine for maps, messaging, and a bit of scrolling, and less fine if you plan to stream in 4K all afternoon. Second, a travel eSIM is data only. You get internet but no local phone number, so you cannot receive a Thai SMS. For most people that does not matter, because WhatsApp and the rest run fine over data. It matters for one specific thing, which I will come back to.
Local SIM card: better for long stays and local numbers
The two networks worth knowing are AIS and True. AIS is the biggest, has the widest coverage, and was rated the fastest network in the country in the 2025 Speedtest awards. True is what you get after TrueMove and dtac merged a couple of years back, and it is a solid second. You will see tourist packages from both at the airport, in their shops, and in any 7-Eleven.
You can grab a tourist SIM at the airport right by baggage claim, which is genuinely handy. Bring your passport, because by law the SIM has to be registered to you. Prices run from about 49 baht for a tiny one day plan up to around 1,599 baht for the longer unlimited ones, and the per day cost drops the longer the validity you buy.
Here is the thing a local SIM does that an eSIM usually cannot: it gives you a local Thai number. That sounds minor until you try to register for Grab or a delivery app and they send a one time code by SMS to a +66 number you do not have. If you are staying a while and you want to use the apps locals use, a local number saves you real headaches. A tip from living here: plenty of people buy the cheaper local SIM and then top up data through the carrier app, which works out far cheaper than the tourist packages once you are set up.
If you stay past 60 days on a tourist SIM, the regulator requires you to reconfirm your identity, usually by texting your passport number to a short code or popping into a shop. Worth knowing if you are the type who comes for two weeks and leaves three months later, which happens here more than you would expect. The current details are on AIS if you want the specifics.
Check your phone before you do anything
This is the step people skip and then get stuck at the airport, so do it now, at home, while you are reading this.
Your phone needs two things to use an eSIM. It has to be eSIM compatible, and it has to be unlocked. On iPhone, eSIM has been supported since the XS and XR back in 2018, so anything from then on is fine. If you are not sure, Apple keeps an official list of which models use an eSIM, and you can check yours against Apple’s page. On most phones you can also dial *#06# and look for an EID number, which tells you the phone can take an eSIM.
The unlocked part trips people up too. If you bought your phone on a contract from a carrier back home and never paid it off or unlocked it, it may refuse a foreign SIM or eSIM entirely, even when the hardware supports it. Sort that out before you fly, not at a Bangkok airport help desk.
One more wrinkle for newer iPhones. If you bought an iPhone 14 or later in the United States, it is eSIM only and has no physical SIM slot at all, so an eSIM is your only option anyway. Not a problem, just something to know.
Pocket Wi-Fi: a shrinking use case
A pocket Wi-Fi is a small rentable box that creates a personal Wi-Fi network for several devices at once. There was a time when this was the standard choice for travellers, and it still has its moments.
It makes sense if you are moving as a group and want phones, tablets, and a laptop all online through one connection, or if your phone is too old for an eSIM and you would rather not deal with a physical SIM. The downsides are that it is one more gadget to carry, it needs charging, and it does you no good when you wander off and leave it back at the hotel. Between eSIM hotspot sharing and cheap local data, I rarely see a strong reason to rent one anymore, but it is there if your situation fits.
What coverage is actually like, especially on the islands
City coverage is excellent. Bangkok, Chiang Mai, Phuket town, and Pattaya all have fast 4G and proper 5G in the busier areas. You will not think about your signal once.
The islands are where it gets more honest. On Koh Phangan, Koh Samui, and Koh Tao the populated parts are well covered, and I run my whole life and work off mobile data here without much drama. But head to a quiet beach on the far side of an island, or up into the hills, and the signal thins out or drops. AIS tends to hold up best in the awkward spots, which is part of why it is the network I lean on. If reliable coverage in the remote corners matters to you, that is the one I would build around.
So what should you actually do
For most visitors, an eSIM before you fly is the right answer. It is the least hassle, you are connected the second you land, and you never queue at a SIM counter.
Get a local SIM instead if you are staying a long stretch or you specifically need a Thai number for Grab, LINE, and the delivery apps. Rent a pocket Wi-Fi only if you have a group to keep online or a phone that cannot do eSIM.
Whatever you pick, sort it before you arrive, and check tonight that your phone is eSIM ready and unlocked rather than finding out at the airport. Thailand is an easy place to stay connected once you have made that one decision. Get it done early and you can spend your first evening finding dinner instead of hunting for a signal.
