2023, the year travel bounced back after the pandemic, saw the tourism industry roar back to life. According to statistics from Taiwan's Tourism Bureau, the top three destinations Taiwanese travellers chose after borders reopened were Japan, China, and Korea.

When it comes to travelling in Korea, most travellers head straight to the capital, Seoul — so how do you buy a Seoul data SIM that keeps you online smoothly, without hitting lag issues while there?

Today's article breaks down Korea's internet speed and compares Korea's 3 major carriers, so you can choose the right Seoul data plan with confidence!

Is Seoul's internet fast?

How is the internet speed in Seoul, Korea? Is it too slow, or is signal generally poor?

According to the UK-based network speed monitor OpenSignal, South Korea's 5G coverage and speed are recognized as world-class, with Seoul's average download speed exceeding 400Mbps — making it the only country in the world where every carrier's download speed surpasses 400Mbps.

For comparison, Taiwan's average speed sits around 224Mbps — over twice as slow as Korea's. It's easy to imagine, then, just how impressive your internet experience will be while travelling in Seoul.

Comparing Korea's 3 major carriers

In Taiwan, we all know the major carriers as Chunghwa Telecom, Taiwan Mobile, and FarEasTone — so which carriers are best known in Korea, and how do they differ from each other?

Korea carrier 1: KT

KT is Korea's largest carrier, holding over 50% market share — somewhat like Chunghwa Telecom's status in Taiwan, and the leading carrier in Korea.

Looking at KT's coverage map below, nearly every major city has at least 4G coverage, and Seoul especially enjoys near-citywide 5G service.

Korea carrier 2: SK Telecom (SKT) 

SKT is Korea's second-largest carrier, also boasting excellent coverage. Compared to KT, SKT's coverage map below shows even broader reach, leaning more heavily toward 5G signal (especially in Seoul and Busan).

While Korea's rural areas generally rely on 3G, this rarely causes issues for most travellers, since most visit major cities — so it's fairly uncommon to drop below 4G (unless heading deep into the mountains).

Korea carrier 3:  LG U+

Most people probably associate LG with home appliances, but in Korea, LG is actually a massive conglomerate offering far more than just electronics and appliances. One of its subsidiaries, LG U+, focuses specifically on mobile and internet services, and is currently Korea's third-largest carrier.

While LG U+ lagged a bit behind the other two carriers during the 3G era, it has aggressively pushed into the market since 4G and 5G launched, and its services and speeds are absolutely on par with the other two major carriers.

LG's coverage map makes this clear — its services run predominantly on 4G and 5G, and even outside Seoul, you'll still find 5G access. Jeju Island, in particular, enjoys near-complete 5G coverage that the other two carriers can't quite match.

Recommended Seoul data SIMs

By this point, you should have a good grasp of Korea's internet speed and carriers, so getting online during your Seoul trip is nothing to worry about.

But here is the real question: which Seoul data SIM, Korea data SIM, or Korea SIM card, should you actually buy?

Here is a look at the different Seoul SIM plans offered by DJB, a company specializing in travel data SIMs:

Recommended Seoul SIMDJB Korea Travel cardDJB Korea card (unlimited data)DJB Korea Pass
CarrierKTSKTKT
Data5/8/10/15/20/30GB, throttled after capUnlimited, no throttling500MB/1GB/2GB daily, throttled after cap
Unlimited data
Calls included?NoNoNo
Can share as hotspot?YesYesYes

Looking at what's currently available, Seoul data SIMs mostly partner with KT and SKT, with LG U+ being relatively rare. One thing to note: Seoul data SIMs cannot make calls to mobile or landline numbers (LINE calls work fine), but you can still share the connection with friends as a hotspot.

Worth noting: no matter which Korea SIM plan you choose, always pay attention to the data allowance and validity period — carriers generally aim to meet the needs of both tourists and business travellers alike in Seoul.

As for the common question, "Do I need an unlimited plan for a Seoul data SIM?" — our advice is to choose based on your trip length and personal needs.

For example: if you're only visiting Seoul for 4-5 days, and your data needs are mainly checking in on social media, texting on LINE, or making voice/video calls, 5-10GB should generally be plenty. But if you have heavy data needs like gaming, streaming video, or uploading videos, then you might want to consider an unlimited plan!

Further reading:
>> Before visiting attractions in Seoul, Korea, get to know the internet, transport, payment methods and must-have apps
>> A guide to Korea's top 10 cherry blossom spots: don't miss these dates for Seoul and Busan's blossoms
>> How do Korea's 4 bus colors work? A detailed guide to riding buses in Korea, even without knowing Korean