How do you choose a Thailand data SIM? We recommend comparing a few options and picking a Thailand data SIM based on 3 factors: which local carrier it runs on, how much data you need, and whether you need calling. In this article, we'll compare common ways to get online in Thailand, including a data SIM, pocket Wi-Fi router, and traditional carrier roaming, to help you quickly find the best option for you — let's dive in!

Comparing Thailand internet options: data SIM, pocket Wi-Fi, or carrier roaming

First, you'll want to know: besides free local Wi-Fi, what other ways are there to get online in Thailand?

Generally, there are three options — here's a table breaking down the differences:

OptionThailand data SIMPocket Wi-Fi routerHome carrier roaming
How it worksBuy a physical SIM card and swap it in once abroadRent a Wi-Fi router from a provider; connect to it once turned onActivate roaming through your home carrier
Calls/texts included?Depends on the planNoYes
Highlights• Affordable, and works with your own phone
• Wide range of plans to choose from		• Priced by day, no speed cap
• One device shared among a group, better value overall		• No SIM swap or rental device needed
• Still able to send/receive calls and texts to your home number while abroad
Best forHeavy data users, independent travellers, backpackersGroups travelling togetherShort trips/business travel, light data users

How do you choose a Thailand data SIM?

There are many ways to get online in Thailand, but we recommend a physical data SIM above all — not just for the lower price, but for the wide range of plans available.

With so many retailers selling Thailand data SIMs online, how do you decide? Here are 3 things to consider:

1. The local carrier

Just like Taiwan has Chunghwa Telecom, Taiwan Mobile, FarEasTone, Taiwan Star, and Asia Pacific Telecom, Thailand has three carriers: AIS, Truemove, and DTAC. All three offer travel data SIM plans, with prices varying by duration, data allowance, and whether calling is included.

AIS is Thailand's largest carrier, somewhat comparable to Chunghwa Telecom's position in Taiwan. While it's a big company with strong signal, its popularity means speeds can slow down in crowded areas.

Truemove and DTAC are more comparable to Taiwan Mobile and FarEasTone — while they may have fewer towers than AIS, their signal and speed tend to be more consistently stable.

2. How much data you need

Data allowance tends to be travellers' top concern — many Taiwanese are used to unlimited plans at home and naturally worry about running short abroad, often leaning toward a Thailand unlimited data plan.

In reality, we recommend just getting enough data for your needs — especially if you're only in Thailand for four or five days, there's really no way you'd use 100-200GB, right? (Unless you're a YouTuber who needs to upload videos)

On top of that, many plans marketed as "unlimited" actually only run at full speed for the first 2-3GB before throttling kicks in — so choose carefully.

3. Does it support calls

These days, most people have LINE installed and handle calls almost entirely through the app — very few people actually dial a phone number anymore.

But some situations abroad still call for a phone number — booking a restaurant, arranging a private driver with a set itinerary, or getting separated from friends with no signal.

If you're worried about running into any of these situations during your trip, be sure to check whether your Thailand data SIM includes calling functionality before you buy!

Where can you buy a Thailand data SIM?

1. Dedicated SIM retailers

Not everyone realises there are companies dedicated to selling travel SIM cards. These companies generally have relevant telecom expertise and their own dedicated infrastructure connected directly to Thai carriers, giving you a stronger guarantee of quality.

Take DJB's Thailand data SIM as an example — the range of plans is genuinely varied, including 50GB over 10 days and genuinely unlimited data with no throttling. If you're travelling across several countries in one trip, DJB also offers a multi-country SIM, perfectly covering your data needs across different destinations.

2. Shopee

Searching Shopee for a Thailand data SIM turns up all kinds of sellers and plans.

The upside of buying a Thailand data SIM on Shopee is the low price, but the downside is not knowing where the SIM actually comes from. Checking reviews carefully, you'll find some SIMs have issues like expiring before use, duplicate numbers, or unstable signal — choose carefully.

3. Travel service platforms

Well-known travel platforms like Klook and KKday also sell Thailand data SIMs. Buying through these platforms tends to mean more consistent quality, with the option to have it shipped ahead of time or pick it up at the airport on the day.

The downside is that they are essentially middlemen — if you run into any issues once abroad, their support may not be able to answer more technical questions.

4. At the local airport

Finally, you can also buy a Thailand data SIM directly in the arrivals hall once you land in Thailand.

The upside is a staff member sets it up for you on the spot, so there is no risk of a SIM that will not work; the downside is that if you are on a tight schedule, setting aside about 30 minutes to buy a data SIM could feel like wasted time.

Further reading:
>> Which months are best for a Thailand trip? A complete guide to things to know, essential for planning your itinerary
>> How do you apply for a Thai visa? 3 common types explained, plus 7 documents you'll need to enter the country
>> Hotels in Hua Hin with a private beach? 9 great-value Hua Hin stays, even favored by Thailand's royal family for a getaway