What is an eSIM and how does it work?
An eSIM is a digital SIM card built directly into your phone. Instead of inserting a plastic card, you download a mobile plan straight to your device and connect in minutes. The "e" stands for embedded, meaning the chip is already inside your phone and gets programmed remotely.
With Firsty you can try a real eSIM right now for free. No payment, no contract, no plastic card. Watch a short ad in the app and get mobile data, at home or in 185+ countries abroad.
How does an eSIM work?
A physical SIM is a small plastic chip you slot into your phone. An eSIM does the same job of identifying you to a mobile network, but the chip is already built into your device and gets programmed digitally. The technical name for it is an eUICC, embedded Universal Integrated Circuit Card, but you will rarely see that term outside the industry.
Here is what actually happens from start to finish. You pick a plan from an eSIM provider like Firsty, and the eSIM profile downloads to your phone through an app, a QR code, or automatically over the air using something called Remote SIM Provisioning. Your phone then uses that profile to authenticate you to a mobile network and you are online. No card swapping, no store visit, no waiting for delivery.
Behind the scenes, your eSIM contains a secure element, a small tamper-resistant chip that encrypts your network credentials. That is what keeps your identity safe on the network, the same way a physical SIM does, only harder to compromise because the chip cannot be removed. Once installed, an eSIM behaves exactly like a physical SIM, the only real difference is that everything happens digitally, in minutes, and it all lives inside your phone.
eSIM vs physical SIM, what is the difference?
| Physical SIM | eSIM | |
|---|---|---|
| Form | Plastic card you insert | Chip built into the phone |
| Setup | Insert card, sometimes visit a store | Download digitally in minutes |
| Switching plans | Swap the card | Download a new profile |
| Lost or stolen | Yes, can be removed | No, it cannot be removed |
| Multiple plans | One card at a time | Store several, run two at once |
| Environmental impact | Plastic and packaging waste | No physical materials |
The practical upshot is that an eSIM lets you add a plan without touching your phone's hardware. You can keep your normal number active on a physical SIM and run a Firsty eSIM alongside it for data on top. That is why eSIM is ideal for travel, for a free backup line, and for anyone who does not want to deal with sim card slots and postal delivery.
For a deeper side-by-side, see our full guide on whether an eSIM is better than a physical SIM.
Why an eSIM is worth switching to
The reason eSIM has taken over so quickly is that it removes friction from every part of mobile connectivity, and especially from travel.
No more airport kiosks or tiny SIM packaging. You do not need to hunt for a local SIM in a foreign country, deal with a pin to eject the tray, or worry about losing a physical card in transit. Your Firsty eSIM lives inside your phone from the moment you install it.
Switching plans takes seconds. Because the profile is digital, changing carriers or destinations happens in the app. There is no waiting for a new SIM to arrive, no calling customer support, no visits to a store.
You can run multiple plans on one phone. Most modern devices let you keep your primary number active on a physical SIM while running an eSIM alongside it for data. Some newer phones support several eSIM profiles at once, so you can have separate profiles for work, personal, and travel.
It is more secure than plastic. An eSIM cannot be physically removed, which makes it much harder to steal than a SIM card. The secure element on the chip protects your credentials, and providers can push security updates remotely.
It is more sustainable. Over 6 billion physical SIM cards are produced globally each year, along with their plastic packaging. eSIM removes that waste entirely.
Phones can be built better. Without a SIM tray, manufacturers have more space for battery, better water resistance, and slimmer builds. That is why iPhone 14 and newer in the US ship eSIM-only.
Is my phone eSIM compatible?
Most phones released since 2018 support eSIM. That includes iPhone XS, XR, SE (2020 and later), all iPhone 11 through iPhone 17 and iPhone Air, plus recent Samsung Galaxy, Google Pixel, and many Android devices from brands like Motorola, Oppo, and Xiaomi.
Quick check on iPhone: Settings, then Cellular, then Add eSIM. If you see the option, your phone is compatible.
Quick check on Android: Settings, then Network and internet, then SIMs, then Add eSIM. The exact path can vary slightly by manufacturer.
A few things worth knowing. Some devices bought in mainland China, Hong Kong, and a handful of other regions ship without eSIM support, even if the same model supports it elsewhere. Your phone also needs to be carrier-unlocked to use an eSIM from a provider other than your home carrier. If you are not sure, see the full compatibility guide or check your device's IMEI with your carrier.
How to get an eSIM
Getting an eSIM used to mean going through your carrier, waiting for an activation code, and hoping the setup worked. With Firsty it takes a few minutes and the first eSIM is free.
Download the Firsty app from the App Store or Google Play
Activate your free eSIM. The app sets it up automatically, no QR code needed
Watch a short ad in the app and you are connected
No contract, no credit check and no registration hassle. If you need more, you can buy data from €0.98 per GB or go unlimited from €2 per day.
For a full walkthrough, follow these steps
Why choose Firsty
Most eSIM providers ask you to pay before you can try anything. Firsty does not. You can use a real eSIM for free, watch a short ad instead of paying, and see how it works with zero commitment.
Firsty works in 185+ countries on one eSIM, so you do not need a new plan every time you cross a border. It runs alongside your existing physical SIM, so you can keep your normal number and add free data on top. You can pause paid days when you do not need them, resume later, and use the same eSIM across multiple destinations. And if you decide to upgrade, plans start at €0.98 per GB or €2 per day for unlimited.
That combination, genuinely free access plus flexible paid plans on one global eSIM, is what makes Firsty different. You get to actually try it before you commit, in the country you are already in or the one you are about to land in.
Frequently Asked Questions
Is an eSIM free?
With Firsty, yes. You can use mobile data for free by watching short ads in the app. Most other eSIM providers charge from the start.
Can I have an eSIM and a physical SIM at the same time?
Yes. Almost all eSIM-compatible phones support dual-SIM, so you can keep your normal SIM active for calls and texts and run a Firsty eSIM alongside it for data.
Does an eSIM work abroad?
Yes. A Firsty eSIM works in 185+ countries with no roaming fees. You install it once and use it everywhere.
Can an eSIM be hacked or stolen?
An eSIM cannot be physically removed from your device, which makes it much harder to steal than a plastic SIM. The credentials on the chip are encrypted and can be updated remotely by your provider.
Do I need a new phone number for an eSIM?
No. You can use a Firsty eSIM as a data-only line while keeping your existing number on your main SIM.
How long does it take to set up an eSIM?
A few minutes. With Firsty, the app configures the eSIM automatically with no manual setup or QR code needed.
What is Remote SIM Provisioning?
Remote SIM Provisioning, or RSP, is the standard that lets your phone download an eSIM profile over the air, without needing anything physically inserted or connected. It is the technology that makes eSIM possible.
Can I switch my eSIM to a new phone?
Yes, but the process depends on your provider. With Firsty, you can transfer your account by signing in on the new device. Some carriers require you to contact them to move the profile.
Do all carriers support eSIM?
Most major carriers now do, but not all. Firsty gives you a way in even if your local carrier does not offer eSIM, since it works independently on any unlocked eSIM-compatible phone.
Do eSIMs support 5G?
Yes. Most modern eSIMs, including Firsty, support 5G as long as your device is 5G-capable and the mobile network you connect to offers 5G in that area. You get the same speeds you would on a physical SIM, no compromise.
Are there any downsides to eSIM?
A few worth knowing. Moving an eSIM between phones is not as simple as popping out a plastic card, most providers require you to reinstall or transfer through their app. Not every device supports eSIM yet, particularly older phones and some models sold in mainland China and Hong Kong. And a small number of local carriers still do not offer eSIM plans, though this is changing quickly. For most travelers and frequent switchers, the tradeoffs are well worth it
