Do I need an eSIM for South Korea?

You don't need one, but it's usually the fastest way to get connected without visiting a telecom shop.

Will my eSIM work on the KTX high-speed train?

SK Telecom and LG Uplus both cover the main rail corridors well, so yes, in most cases.

Is 5 GB enough for two weeks in South Korea?

For normal use (maps, messaging, some social media), yes; heavy streaming will use it faster.

Can I keep my home number active alongside the eSIM?

Yes, the eSIM runs as a second line for data while your physical SIM stays active for calls and texts.

What happens when I run out of data on a non-unlimited plan?

On ONE eSIM's fixed-data plans you can buy a top-up; on daily-cap plans, speed drops rather than cutting off.

Best eSIM for South Korea 2026: 5 Providers Priced

South Korea eSIM prices checked 27 Oct 2026: ONE eSIM is cheapest at every size from 1 to 20 GB, from $1.93 for 1 GB.

Short answer: ONE eSIM has the cheapest 1 GB eSIM for South Korea at $1.93 for 7 days; the next cheapest is Saily at $3.99. Prices checked 27 October 2026 across ONE eSIM, Airalo, Holafly, Saily and Nomad; the full table is below.

Between Seoul's tech-heavy streets, K-pop culture stops and fast intercity transit, reliable data matters from the moment you land at Incheon. An eSIM gets you online without queuing at a SIM counter. On 27 October 2026 we compared prices for ONE eSIM, Airalo, Holafly, Saily and Nomad in South Korea.

Quick answer: South Korea eSIM prices by size

1 GB: ONE eSIM at $1.93 (7 days); next cheapest is Saily at $3.99 (7 days).
3 GB: ONE eSIM at $4.68 (15 days); next cheapest is Airalo at $8.00 (3 days).
5 GB: ONE eSIM at $7.43 (30 days); next cheapest is Airalo at $10.00 (7 days).
10 GB: ONE eSIM at $12.93 (30 days); next cheapest is Airalo at $18.00 (7 days).
20 GB: ONE eSIM at $22.55 (30 days); next cheapest is Nomad at $28.00 (30 days).

South Korea eSIM prices compared (1 GB to 20 GB)

South Korea eSIM prices in USD: each provider's cheapest plan at or above the size, validity in brackets. Cheapest marks the lowest price. Where another provider is cheaper, a note under ONE eSIM shows where it still wins: more data for the money, a lower price per GB, or more days. Checked 27 October 2026.
Data	ONE eSIM Our price	Airalo	Holafly	Saily	Nomad
1 GB	$1.93 (7 days) Cheapest, saves $2.06	$4.00 (3 days)	–	$3.99 (7 days)	$4.00 (7 days)
3 GB	$4.68 (15 days) Cheapest, saves $3.32	$8.00 (3 days)	–	$8.99 (30 days)	$8.00 (30 days)
5 GB	$7.43 (30 days) Cheapest, saves $2.57	$10.00 (7 days)	–	$10.99 (30 days)	$10.00 (30 days)
10 GB	$12.93 (30 days) Cheapest, saves $5.07	$18.00 (7 days)	–	$18.99 (30 days)	$20.00 (30 days)
20 GB	$22.55 (30 days) Cheapest, saves $5.45	$29.00 (15 days)	–	$29.99 (30 days)	$28.00 (30 days)

Holafly sells only unlimited plans for South Korea, so it has no price in the GB rows; its 7-day plan is in the week table below.

A week of unlimited data in South Korea

7 days of unlimited data in South Korea: ONE eSIM's daily plan bought for 7 days against 7-day unlimited plans, with what each gives a day. USD, checked 27 October 2026.
Provider	7 days	What you get
ONE eSIM	$15.40	1 GB a day at full speed, then 1 Mbps until the next day (7 × $2.20)
Airalo	$29.00	3 GB a day at full speed, then 1 Mbps (fair use)
Holafly	$27.50	No daily cap; fair use may slow very heavy use
Saily	$26.99	5 GB a day at full speed, then up to 1 Mbps
Nomad	$25.00	2 GB a day at full speed, then 512 Kbps

For a week, ONE eSIM's 1 GB a day plan is the cheapest way to stay online all day at $15.40. The cheapest of the others is Nomad at $25.00, which gives more full-speed data a day; compare by how much you use a day, not by the word unlimited.

Networks and coverage in South Korea

ONE eSIM's South Korea plans run on SK Telecom and LG Uplus, both listed with 5G. These two networks between them cover Seoul, Busan and the rest of the country well, including most of the high-speed rail network.

Which eSIM should you choose for South Korea?

Short trip, light use (up to 3 GB): ONE eSIM's 3 GB plan at $4.68 (15 days), the cheapest at that size.
Two weeks or more (5 to 10 GB): ONE eSIM's 10 GB plan at $12.93 (30 days), the cheapest at that size.
Heavy use (20 GB): ONE eSIM's 20 GB plan at $22.55 (30 days), the cheapest at that size.
Streaming or video calls every day: compare the unlimited plans above by how much full-speed data each gives a day.

How to set up your South Korea eSIM

Check your phone supports eSIM (most iPhones since the XS and Android flagships since 2019 do).
Buy and install the eSIM on Wi-Fi before you fly, so the QR code or install link downloads without using mobile data.
Turn on the new eSIM line and enable data roaming once you land in South Korea, then switch off your home SIM's data to avoid charges.

South Korea eSIM FAQ

Do I need an eSIM for South Korea? You don't need one, but it's usually the fastest way to get connected without visiting a telecom shop.
Will my eSIM work on the KTX high-speed train? SK Telecom and LG Uplus both cover the main rail corridors well, so yes, in most cases.
Is 5 GB enough for two weeks in South Korea? For normal use (maps, messaging, some social media), yes; heavy streaming will use it faster.
Can I keep my home number active alongside the eSIM? Yes, the eSIM runs as a second line for data while your physical SIM stays active for calls and texts.
What happens when I run out of data on a non-unlimited plan? On ONE eSIM's fixed-data plans you can buy a top-up; on daily-cap plans, speed drops rather than cutting off.

How we check prices

We read each provider's public South Korea page on 27 October 2026 and took its cheapest plan at or above each size, in US dollars before any coupon, with the validity in brackets; ONE eSIM prices are our live list prices on the same day. Prices move, so we re-check every month and keep the date on the page and in the short answer. If a number is out of date, write to support@oneesim.app and we will correct it.