Staying online in Korea is easy and cheap, and you've got three good options. The only real question is which one suits your phone and your trip. Here's the plain version.
eSIM: easiest, if your phone supports it
If your phone is eSIM-compatible (most recent iPhones and flagship Androids are), this is the smoothest route. You buy a Korea eSIM online, install it before you fly, and it switches on the moment you land, with no counter and no queue. It's my default for a short trip. Just confirm your phone supports eSIM before you buy.
Physical SIM card: works on any unlocked phone
Korea has three carriers, KT, SK Telecom, and LG U+, and all three sell tourist SIMs valid from one day up to 90 days. You can grab one at a counter in the Incheon Airport arrivals hall, or pre-book online and collect it there. You'll need your passport to buy and activate it, and your phone has to be unlocked to accept a foreign SIM.
Pocket WiFi: best for groups
A pocket WiFi device, sometimes called a WiFi egg, is a small router you carry that connects several devices at once. It makes the most sense if you're traveling as a family or group sharing one connection, or if your phone can't take an eSIM or a foreign SIM. You rent it at the airport and return it when you leave.
Which should you choose?
- Solo with a modern phone: an eSIM. Set it up before you land and forget about it.
- Phone with no eSIM: a physical SIM from an airport counter.
- Family or group: one pocket WiFi to share.
Two things people forget
- Bring your passport. It's required to buy any SIM in Korea.
- Check your phone first. It must be unlocked for a SIM, or eSIM-capable for an eSIM. Prices vary by days and data, so compare a couple of options before you commit.
Carrier and SIM details here are checked against KTO VisitKorea and Incheon Airport. Plans and prices vary, so compare before you buy.