Before our trip to Krabi, we did what we always do now: bought an eSIM before leaving home.
Two of us, two different plans. Sixteen days later, one of us had used 4 GB and the other 17 GB.
That gap is the whole reason we wrote this.
Every eSIM guide tells you to buy one. Almost none tell you how much data you’ll actually need — and getting that wrong costs you either money or a very slow last few days.
Why we don’t rely on hotel WiFi
The usual argument for a travel eSIM is roaming charges. Ours is different.
There’s usually free WiFi available. It just doesn’t work where you actually are.
On several of our earlier trips, the free hotel WiFi was genuinely fast — in the lobby. In reception. By the pool bar.
Back in the room, it dropped to something that couldn’t load a photo, let alone upload one.
Great WiFi in the lobby is not the same as WiFi in your room.
To be fair, our hotel in Ao Nang was one of the good ones. The WiFi worked properly, even in the room.
We still switched over to mobile data more than once when we needed real speed.
There’s one more reason, and it has nothing to do with speed.
When we land in a country on the other side of the world, the people at home want to know we arrived safely. Having a connection the moment the plane doors open means we can tell them straight away — instead of hunting for airport WiFi first.
How much data do you actually need?
Here’s what happened over our sixteen days in Krabi.
Same trip. Same destination. Same eSIM provider.
| Plan bought | Actually used | |
|---|---|---|
| Anna-Liisa | 5 GB | 4 GB |
| Argo | 20 GB | 17 GB |
A fourfold difference between two people on the same holiday.
Anna-Liisa’s usage was what most travellers look like: maps, messaging, social media, the occasional video call home, photos posted along the way.
Four gigabytes over just over two weeks.
Argo worked during the trip. That meant everything a normal working day involves, plus uploading our own travel photos and video.
Seventeen gigabytes.
Both of us happened to buy the right plan — but only just. Anna-Liisa had 1 GB spare. Argo had 3 GB spare across sixteen days.
Neither of us had much room to spare.
If you use your phone the way you do at home, 5 GB is likely plenty for two weeks. If you work, upload video or make long video calls, plan for four times that.
What actually uses the data
The reason for the gap becomes obvious once you look at what different activities consume.
These are rough figures. Quality settings and app behaviour change them a lot — but they’re enough to estimate with.
| What you’re doing | Roughly |
|---|---|
| Messaging apps, a full day | under 10 MB |
| Maps navigation, one hour | 5–10 MB |
| Uploading one phone photo | 3–5 MB |
| Scrolling social media, 30 minutes | 150–250 MB |
| Video call, one hour | 500 MB – 1.5 GB |
| Streaming video in HD, one hour | ~3 GB |
| Uploading one minute of 4K video | 350–400 MB |
Look at the last two rows and the gap explains itself.
A few video calls and some uploaded footage will out-consume a fortnight of maps and messaging without any trouble at all.
Is the unlimited plan worth it?
This is where “unlimited” needs a closer look, because it isn’t.
Saily’s unlimited plans run on a fair usage policy: 5 GB per day at full speed, after which the connection is throttled to around 1 Mbps until the 24-hour cycle resets.
That’s fine for maps and messages. It is not fine for uploading anything.
Now do the maths on our own trip.
Seventeen gigabytes across sixteen days is roughly one gigabyte a day. Even on the heavier of our two plans, we never came close to the 5 GB daily ceiling.
Unlimited would have been the wrong purchase for both of us.
At the time of writing, unlimited costs €34.49 for fifteen days. The 20 GB plan that turned out to be enough costs €17.99 and runs for thirty. Half the price, twice the window.
Unlimited makes sense if you genuinely stream for hours every day, or you’re travelling for months rather than weeks. For a two-week holiday, a fixed plan is almost always cheaper and does the same job.
If you decide a Saily plan suits your trip, the link below is an affiliate link. It costs you nothing extra and helps keep this site running — see our affiliate disclosure for how that works.
Check current Saily plans for Thailand →
Setting it up before you fly
This is the part people worry about, and it takes about five minutes.
- Buy the plan for your destination and install the eSIM — either by scanning the QR code you’re sent, or through the provider’s app.
- Enable data roaming for that eSIM profile. This is the step people skip, and it’s the one that causes “it didn’t work when I landed”.
- Leave your normal SIM active for calls and texts. The eSIM handles data only.
- Fly. The plan activates by itself when you arrive.
We set ours up at home, days before leaving.
When we landed at Krabi airport, both phones were online before we reached passport control. No hunting for airport WiFi. No queue at a SIM counter.
One detail worth knowing: the plan activates when you arrive or 30 days after purchase, whichever comes first.
If you’re booking a trip further out than that, buy the eSIM closer to departure.
If it doesn’t connect
It worked immediately for both of us. It doesn’t for everyone.
Travel eSIM providers don’t own the towers. They resell access to local partner networks, which is why the same product can feel flawless in one country and stubborn in another.
If you land and have no data, work through this before contacting anyone:
- Check that data roaming is enabled for the eSIM profile, not just your main line
- Check that the eSIM is selected as your mobile data line
- Turn on aeroplane mode for about twenty seconds, then off again — this forces the phone to re-register with local towers
- If you have signal bars but no data, check the APN setting in your provider’s app or activation email
Questions people ask
How much eSIM data do I need for two weeks in Thailand?
For normal holiday use — maps, messaging, social media, some photos — 5 GB was enough for one of us across sixteen days. If you’re working, making long video calls or uploading video, budget 15–20 GB.
Does the eSIM work as soon as you land?
Ours did, at Krabi airport, on both phones. The condition is that you installed it beforehand and enabled data roaming for that profile.
Can you keep your own phone number?
Yes. The travel eSIM handles data; your normal SIM stays active for calls and texts. Just make sure your own line’s data roaming is switched off so it doesn’t quietly run up charges.
Is the unlimited plan really unlimited?
No. There’s a fair usage limit of 5 GB per day at full speed, after which you’re throttled until the next day. For most trips a fixed plan is cheaper and does the same job.
Do you still need hotel WiFi?
It helps, when it works. Our Ao Nang hotel had good WiFi in the room, which isn’t always the case — on earlier trips we’ve stayed in places where the free connection was only usable in the lobby. Having mobile data means it doesn’t matter either way.
Can you top up mid-trip?
Yes, through the app. That’s worth remembering if you’re torn between two plan sizes — starting smaller and topping up costs less than buying data you never use.
Practical Information
- What we used: Saily eSIM, data only, alongside our normal SIMs
- Our usage, 16 days: 4 GB (normal use) and 17 GB (working + uploading video)
- Thailand plans, August 2026: 1 GB / 7 days €2.49 · 3 GB €5.49 · 5 GB €6.99 · 10 GB €9.99 · 20 GB €17.99 (all 30 days) · unlimited €34.49 (15 days)
- Unlimited: 5 GB per day at full speed, then throttled to about 1 Mbps
- Activation: automatic on arrival, or 30 days after purchase — whichever comes first
- Before you fly: install the eSIM and enable data roaming for that profile
- Your own number: stays active — the eSIM is data only
Final thoughts
If there’s one thing we’d pass on, it’s that the plan size matters more than the provider.
Two people on the same trip, using the same service, needed wildly different amounts. Neither of us could have guessed that in advance without doing the sums first.
Work out what you actually do on your phone, look at the table above, and buy accordingly.
You can always top up mid-trip. You can’t get back the money spent on data you never used.
Planning the rest of your trip? Our Krabi travel guide covers where to stay and what to expect in Ao Nang, and getting around Krabi explains how we managed without renting a car — which, as it turns out, relied on having a connection.
How much data do you get through on a two-week trip — and have you ever run out at the worst possible moment? Tell us in the comments.
Based on our own trip to Krabi in February 2026. Prices checked in August 2026 and may have changed since. Last updated: 9 August 2026.
