This data shows actual connection speeds for eSIMs, physical SIM cards, and roaming services measured in South Korea (Seoul, Busan, Incheon, etc.). We hope this information helps you choose the right plan before your trip or business trip.
| # | Career | Average downhill speed | Average uphill speed | Ping |
|---|---|---|---|---|
| 1 | Hutchison Telephone Company | 152.0 Mbps | 13.2 13.2 Mbps | 122 ms |
| 2 | LG U+ | 133.4 Mbps | 26.7 Mbps | 52 ms |
| 3 | SK Telecom | 128.1 Mbps | 18.9 18.9 Mbps | 79 ms |
| 4 | KT | 124.0 Mbps | 10.0 Mbps | 61 ms |
| 5 | SK 7mobile | 22.0 22.0 Mbps | 14.6 Mbps | 51 ms |
| # | Services | Category | Average downhill speed | Average uphill speed | Ping |
|---|---|---|---|---|---|
| 1 | KT | Local SIM | 234.2 Mbps | 4.6 Mbps | 59 ms |
| 2 | LG U+ | Local SIM | 215.6 Mbps | 46.6 Mbps | 46 ms |
| 3 | SK Telecom, LG U+ | eSIM | 152.0 Mbps | 13.2 13.2 Mbps | 122 ms |
| 4 | SK Telecom | Local SIM | 128.1 Mbps | 18.9 18.9 Mbps | 79 ms |
| 5 | U+ Alttum Mobile | Local SIM | 41.8 Mbps | 8.9 Mbps | 59 ms |
| 6 | SK 7mobile | Local SIM | 22.0 22.0 Mbps | 14.6 Mbps | 51 ms |
South Korea is a mobile technology leader that boasts some of the world’s fastest internet speeds. According to a 2025 survey by the Korea Telecommunications Operators Association (KTOA), South Korea’s average 5G download speed is approximately 1,025 Mbps—about 3.8 times faster than the average (approximately 268 Mbps) among seven major countries, including Japan, the United States, and Germany. It is also more than twice as fast as the United States, which has the fastest speeds among the countries included in the comparison.
The average 5G latency (ping) is 20 ms, which is less than half the average of 53 ms across the countries surveyed. With stable connectivity available even in subways and public facilities, this country offers a comfortable smartphone experience for travelers.
The three major carriers are SK Telecom (approximately 40% market share), KT (approximately 30%), and LG U+ (approximately 20%). When travelers use a Korean mobile network via an eSIM or SIM card, they will be connected to one of these three networks, so their actual connectivity experience will vary depending on which carrier they are connected to.
According to the latest actual measurement data from this site for April 2026, the following trends have been observed.
KT recorded the fastest speed in this round of testing, with an average download speed of 234.2 Mbps. Since the test was conducted in the Incheon area, you can expect high-speed connectivity immediately upon arrival at the airport.
SK Telecom has six data points primarily from downtown Seoul, with speeds ranging from a maximum of 280.1 Mbps to a minimum of 21.6 Mbps. The average download speed is 128.1 Mbps. Although there is some variation depending on location and time of day, this dataset is the most extensive and reliable. It is ideal for those who want stable service in Seoul’s major areas.
While LG U+’s average download speed of 36.2 Mbps is modest compared to the other two carriers, its average ping of 53 ms is the lowest, ensuring good response times. This level of performance is more than sufficient for comfortable use in applications that do not require high-bandwidth data transmission, such as map apps and messaging.
Looking at the comparison by service, the eSIM (SKT/LGU+ network) recorded a download speed of 152.0 Mbps, which is on par with local SIM cards. It’s not the case that eSIMs are inherently slower; rather, the carrier and coverage area are the primary factors affecting speed.
However, the fact that the ping value in the eSIM measurement data is slightly high at 122 ms may be due to latency caused by the connection via roaming. Users who frequently make video calls or engage in other activities that require real-time responsiveness should take this into account.
The data is based on users' actual measurements and is automatically updated whenever new results are posted. We recommend checking the latest data before your trip to find out which carriers are available in the area where you'll be staying.
As the actual measurement data shows, there are significant differences in connection speeds in South Korea depending on the carrier and location.
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