"I keep hearing about eSIMs, but I'm not sure what makes them so handy." "It's my first trip abroad, and I'm worried about whether my own phone will actually work." If that sounds like you, this is your starting-point guide to eSIMs. We cover how an eSIM works, how it differs from a physical SIM, the pros and cons, the things to know about data-only plans, how to choose the right amount of data, the setup flow, and what to check when you can't get online—all with as little jargon as possible. With the tables and bullet points, you can also just skim the parts you need.
- An eSIM lets you add a mobile plan online—no swapping cards
- You can set it up on Wi-Fi before you leave and use it as soon as you arrive
- You'll need a compatible, unlocked device
- Data-only plans don't include a phone number, calls, or SMS, but app-based calls (e.g. WhatsApp) can still work
- Rough data guide: 1–3GB for maps, 3–5GB for social media, 10GB+ for video
Connection speed and reliability depend on your device, supported bands, the local network, your location and area, indoor conditions, time of day, congestion, and your settings. This article is for general information only (as of June 2026). Please confirm the latest details on pricing, supported countries, and compatible devices on our comparison page or official guidance before you buy.
What is an eSIM? (How it works, made simple)
An eSIM lets you take the SIM function built into your phone and add a mobile plan to it online. The name is short for "embedded SIM." Instead of swapping a physical card the way you would with a traditional SIM, you load a plan by scanning a QR code or following a simple guided process.
You'll sometimes hear it described as "a SIM built into your phone," but more precisely, the SIM function lives on a chip inside the device, and your plan is written to it digitally. It may help to think of it this way: what used to be a physical "thing"—a card—can now be handled as data.
For trips abroad or longer stays, you can buy and install your plan online before you leave, then start using data the moment you arrive. Not having to hunt for a SIM card at the airport or fiddle with a tiny card is one reason eSIMs are popular with travelers. If you'd like a deeper comparison with physical SIMs, see eSIM vs. physical SIM: differences and comparison.
eSIM vs. physical SIM vs. roaming vs. pocket Wi-Fi
An eSIM isn't the only way to stay connected abroad. Laying out the options side by side makes it easier to spot the one that fits you.
| Option | What it is | Best for | Keep in mind |
|---|---|---|---|
| eSIM | A data plan you add via QR code or a guided process | People who don't want to swap cards and want to set up before leaving | Needs a compatible, unlocked device |
| Physical SIM | A local SIM card you insert into your phone | People who need a local phone number | You have to swap and store the card |
| International roaming | Using your existing plan while abroad | People who want zero setup | Can get expensive |
| Pocket Wi-Fi | A hotspot device several gadgets can share | Groups or multi-device use | You carry, charge, and return the device |
For example, if you want to travel light with just your own phone, an eSIM tends to fit; if your whole family wants to share one connection, pocket Wi-Fi may suit better. Choosing by group size and how you'll use it makes the decision much easier.
The benefits of an eSIM
Here are the points beginners most often appreciate after switching to an eSIM.
- No card to receive or swap: You buy online and set up with a few taps, so there's no tiny SIM card to insert, remove, or lose.
- You can prepare before you leave: Install it calmly on your home Wi-Fi and you'll have almost nothing to do once you arrive—no scrambling for a SIM at the airport.
- Easy to switch between plans and lines: On many eSIM-capable phones, you can keep your everyday line and add a travel eSIM alongside it, switching when needed (exact behavior varies by device and OS).
- Pick just what you need: Because you choose by destination, duration, and data amount, it's easy to match your plan to how you travel—less data for a short trip, more for a longer, video-heavy stay.
Drawbacks and things to watch for
As handy as it is, there are a few things worth knowing. We're sharing these honestly—not to alarm you, but so you're not caught out after buying.
- It only works on compatible devices: You need an eSIM-capable phone. Older models may not support it.
- Your device may need to be unlocked: Phones bought from some carriers may require an unlocking step.
- Moving it to another device can be tricky: Once installed, an eSIM isn't as easy to pop out and move to another phone the way a physical SIM is. If you're planning to change phones, factor that in alongside how long you'll use the plan.
- You need internet to set it up: Scanning the QR code and loading the plan require a connection, so setting up on Wi-Fi before departure is the smoothest approach.
- Data-only plans generally don't include a phone number, SMS, or voice calls: More on this in the next section.
How to check device compatibility and lock status
An eSIM only works on supported devices. The table below is a rough guide (it varies by model, release year, and region of sale—check the latest on our compatible devices page).
| Device | General eSIM support |
|---|---|
| iPhone | Most models from iPhone XS / XR (2018) onward |
| Google Pixel | Most models from Pixel 4 onward (depends on region) |
| Samsung Galaxy | Some newer models, such as Galaxy S20 and later |
How to check if your phone is unlocked: On iPhone, open Settings → General → About and check whether the "SIM Lock" entry shows "No SIM restrictions." On Android, the location varies by model, so check your device maker's or seller's guidance. Phones purchased from some carriers may need an unlocking step first.
A checklist before you use an eSIM
| What to confirm | Key point |
|---|---|
| Is your device eSIM-compatible? | It only works on supported devices. Check the compatible devices page. |
| Is your device unlocked? | You need an unlocked phone. See the device and lock-status check. |
| Does the plan cover your destination? | Confirm coverage for where you're going on the comparison page. |
| Does the duration match your trip? | A little longer than your stay is a safe bet. |
| Is the data amount enough? | Choose based on how you'll use it (see how many GB do you need?). |
| Do you need a phone number, SMS, or voice calls? | If so, prepare an alternative, such as a way to handle SMS verification. |
| When will you install it? | Before departure, while on Wi-Fi, is ideal. See how to set up your eSIM. |
| Will you turn on data roaming after arrival? | Travel eSIMs usually need it on (if you can't connect). |
| Can you access your QR code and purchase email? | Your setup details are also available in My Account. |
What a data-only eSIM can and can't do
Like Bloomy eSIM, many travel eSIMs are "data-only." Data-only means you get internet access, but no phone number of your own. App-based calls and messages—through WhatsApp, for example—can still work whenever you have a data connection.
| Use case | On a data-only eSIM |
|---|---|
| Google Maps | ○ Works over data |
| WhatsApp messages and calls | ○ Works over data |
| Browsing and posting on social media | ○ Works over data |
| Web search | ○ Works over data |
| Ride-hailing apps | ○ Works over data |
| Getting a phone number | × Generally not included |
| Receiving SMS | × Generally not included |
| Voice calls (over a phone number) | × Generally not included |
| SMS verification | △ Needs another method, such as an existing phone line |
This eSIM is data-only. A phone number, SMS, and voice calls are generally not included. For anything that needs SMS verification or a phone number, you may need another option, such as your existing phone line, an SMS-capable SIM, or a local SIM. For more, see how to receive SMS verification codes abroad.
Notes on phone numbers and SMS verification
Banking apps and social-media logins sometimes send a verification code by SMS to your registered number. A data-only eSIM alone can't receive these, so it's worth preparing in one of these ways before you go:
- Keep your everyday phone line active and add the travel eSIM alongside it (if your device supports it).
- Arrange a separate way to receive SMS (a SIM or service that comes with a number).
- Before you travel, review the logins and two-factor settings for the services you use most.
For more on phone numbers, SMS, and calling, see can you use a phone number with an eSIM alone?
How many GB should you choose?
How much data you need depends on how you use your phone. Use the guide below as a starting point.
| Usage / duration | Rough data guide |
|---|---|
| Mostly maps, messaging, and web search | 1–3GB |
| Lots of social-media posting | 3–5GB |
| Lots of video streaming | 10GB+ |
| A short 3–5 day trip | 1–3GB |
| A 1–2 week trip | 5GB+ |
| A multi-country trip | A regional plan (choose data by days and usage) |
Here's a rough guide to how much data different apps and activities use (this varies with quality settings and how you use them).
| Activity | Rough data use |
|---|---|
| Maps (Google Maps) | About 5–10MB per hour |
| Messaging and stickers (e.g. WhatsApp) | A few MB per day |
| App voice calls (e.g. WhatsApp) | About 3MB per 10 minutes |
| Browsing social media (Instagram, etc.) | A few hundred MB per hour |
| Video streaming (standard quality) | About 0.5–1GB per hour |
| Video streaming (high quality) | Several GB per hour |
For example, a 3–5 day trip focused on maps and staying in touch points to 1–3GB; heavy social-media use to 3–5GB; daily video to 10GB or more. If you're unsure, choosing a little extra means you won't have to watch your remaining data so closely on the ground. For more on choosing data, see how many GB do you need for an eSIM abroad?, and if you run into data or connection trouble, see what to check when you can't connect.
From purchase to getting connected
- Choose your destination
- Choose your duration and data amount
- Complete your purchase
- Receive your QR code or installation details
- Install on Wi-Fi before departure or before arrival
- After arriving, set the eSIM as your mobile data line
- Turn on data roaming
- Confirm you're connected
Note: When the validity period starts, and when to install or activate, vary by plan. Please review the plan details before purchasing. For step-by-step instructions by device, see how to set up your eSIM.
What to check if you can't connect abroad
- Confirm your device is eSIM-compatible
- Confirm your device is unlocked
- Confirm your Bloomy eSIM is selected for mobile data
- Confirm data roaming is turned on
- Check whether an APN setting is needed (it's usually configured automatically)
- Try toggling airplane mode on and off
- Restart your device
- If a network isn't selected automatically, choose the carrier manually
- If it still won't work, contact support with your purchase and device details
For detailed fixes by cause, see why your eSIM won't connect abroad, and how to fix it. If you're stuck, you can also use our troubleshooting guide or contact us.
How to choose a plan with Bloomy eSIM
Once you have a sense of how you'll use it, you can narrow things down by your own criteria.
- If your destination is set, compare eSIMs by country.
- If your dates are set, filter by duration.
- If you're unsure about data, compare smaller, mid-size, and larger options.
- If you're visiting several countries, look at a regional plan.
- For longer stays where you want to use plenty of data, the unlimited plan is also an option (please review the terms, including speed management and the fair-use policy, before purchasing).
In summary
An eSIM lets you add a mobile plan online without swapping a SIM card, and it's one of the easiest ways to get mobile data while traveling. The upside is that there's no card to receive or swap and you can set it up before you leave; the trade-off is that you need to check device compatibility and lock status. Bloomy eSIM is data-only, so a phone number, SMS, and voice calls are generally not included. If it's your first time, confirming your device compatibility, lock status, data amount, duration, and setup steps before buying will help you get connected smoothly once you arrive. When you're ready, compare plans by destination and duration to find the right fit.
