eSIM for Japan & South Korea 
Viasimo's Japan & South Korea eSIM starts at $2.59 for 1 GB over 7 days, running on local 5G networks where available. Plans last 3 to 180 days, arrive by email in minutes and install from your phone's settings, with no app.
Plans cover up to 2 countries
Duration
Unlimited data · 3 Days ×1
$11.99
Does my phone take an eSIM? Check now
Dial *#06# on your phone. If you see an EID number, your phone takes an eSIM. Most phones sold since 2019 do.
Not sure it works on your phone? Check compatibilityWhich networks does the Japan & South Korea eSIM use?
The host network is chosen automatically when you arrive.
- Data
- 1 GB – 20 GB or unlimited
- Validity
- 3–180 days
- Speed
- 4G LTE / 5G
- Hotspot / tethering
- Supported on most devices
- Activation
- Starts when you first connect in your destination
- Speed management
- Roughly 2-3 GB per day at full speed, sometimes less depending on the local carrier, then reduced
- Top-ups
- Add more data from your account, before the plan expires
- Text messages (SMS)
- Data only: use an app for verification codes
- Connects via
- Singapore
- Unused validity
- 180 days before it must be installed
How much data do you need?
The allowances below are our sizing recommendations, not measurements. The plan beside each one is the cheapest option on this page that covers it.
| You are | Plan for | Cheapest plan that covers it |
|---|---|---|
| LightMaps, messaging and the occasional lookup | About 1 GB a week | $2.591 GB, 7 days |
| TypicalMaps, social, photos and some browsing | About 3 to 7 GB a week | $9.995 GB, 30 days |
| HeavyVideo streaming, video calls and uploads | 10 GB a week or more | $18.9910 GB, 30 days |
| Working or sharingTethering a laptop, calls and cloud sync | 20 GB a week or more | $25.99Unlimited, 7 days |
eSIM, local SIM or roaming?
Charged per day
Your carrier roaming
Queue and plastic
A SIM at the airport
$2.59
Viasimo, one bundle
Only the Viasimo figure is a price: it comes from today’s live catalog. The other two rows are directional, not quoted rates.
Important to know
- This is a data-only eSIM. It carries no calls or SMS on its own number.
- Your existing number stays on your primary SIM, so calls and verification texts keep working.
- Your phone must support eSIM, and some carrier-locked phones cannot install one.
- Signal varies with location, terrain, congestion and your handset. Dense urban areas are consistently better served than remote ones.
- 5G only works where the host network has deployed it and your phone supports it. Everywhere else it falls back to 4G LTE.
- Unlimited plans run at full speed up to a fair-use limit, then continue at a reduced speed. Read the fair usage policy
Frequently asked questions
Does an eSIM work in Japan & South Korea?
Yes. Your Japan & South Korea eSIM connects automatically the moment you arrive, with no roaming fees and nothing to set up at the airport. Coverage runs on 4G LTE and 5G where the network has rolled it out, and falls back to 4G elsewhere.
Do I get 5G in Japan & South Korea?
Yes, where it has been deployed. 5G runs on The local networks we use in Japan & South Korea, and your eSIM uses it automatically on a 5G-capable phone, dropping back to 4G LTE outside covered areas. No country is covered everywhere, so 5G availability varies by location.
Does Google Maps give walking directions in South Korea?
Not yet. The Korea Herald reported in August 2026 that Google Maps in Korea offered places and public transit routes but still no turn-by-turn walking or driving directions, although the government conditionally approved a map data export in February 2026. Most visitors use Naver Map or KakaoMap, which have English menus.
Is there signal on the ferry from Fukuoka to Busan?
Only near the coasts. On the Hakata to Busan and Shimonoseki to Busan ferries you will have signal near each port but be offline for much of the Korea Strait. Download your boarding pass and directions before boarding. When you arrive, your phone switches to a Korean network, which may take a few minutes.
How do I get earthquake alerts in Japan on a travel eSIM?
Install the Japan National Tourism Organization's Safety tips app. It sends push notifications for earthquake early warnings, tsunami warnings and severe weather, in English and 14 other languages, and works over any data connection. It also includes an evacuation flowchart and useful phrases for asking locals for help.
Which networks will my phone use in Japan and Korea?
In Japan the plan uses SoftBank or KDDI's au network, and in South Korea it uses SK Telecom or LG Uplus. All four have strong 4G and 5G in cities and along the high-speed rail lines. Your phone will show one of these names after you land, and may switch between them in each country.
How much data do I need for 7 days in Japan & South Korea?
For 7 days in Japan & South Korea, Viasimo sells 1 GB for $2.59 and unlimited data for $25.99. Our sizing recommendation, not a measurement: maps, messaging and the occasional lookup, about 1 GB a week; maps, social, photos and some browsing, about 3 to 7 GB a week. The data calculator on this site works it out from how you actually use your phone.
Installing, keeping your number, topping up and hotspot work the same everywhere: see how it works →
Japan & South Korea: what to know before you land
This plan covers Japan and South Korea on one eSIM, using SoftBank or KDDI's au network in Japan and SK Telecom or LG Uplus in Korea. Both countries have fast 5G in cities and strong coverage on their bullet trains. The bigger difference is apps: Google Maps works well in Japan but still lacks walking and driving directions in Korea.
- Emergency
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- 110 police
- 119 ambulance
- 112 police
- 119 ambulance
- Plugs
- ABCF 100V in Japan; 220V in South Korea
- Currency
- Japanese yen (JPY) and South Korean won (KRW)
Main airports
- HND Tokyo Haneda Airport
- NRT Narita International Airport
- KIX Kansai International Airport
- FUK Fukuoka Airport
The Fukuoka and Shimonoseki ferries to Busan
If you want to travel between the two countries by sea, there are ferries between Hakata Port in Fukuoka and Busan, run by Camellia Line, and between Shimonoseki and Busan on the Kampu and Pukwan ferries. Some are overnight sailings that take most of the night.
On these crossings you keep land signal for a while after leaving port and pick it up again as you approach the other coast, but expect to be offline for much of the Korea Strait. Some ships may offer onboard wifi, which is slower than mobile data. Download your boarding pass, arrival directions and the Busan metro map before you board.
When you arrive in Busan, your phone needs to switch from a Japanese to a Korean network. If it does not connect within a few minutes, toggle airplane mode. From Busan Port International Passenger Terminal you can take the metro or a taxi, and Kakao T works well for booking one. The same applies in the other direction when you arrive at Hakata or Shimonoseki.
Shinkansen, KTX and the mountain routes
Both countries' high-speed trains run through well-covered areas, though tunnels cause short dropouts. On Japan's Tokaido Shinkansen between Tokyo, Nagoya, Kyoto and Osaka, and on the Sanyo line to Hiroshima and Hakata, you will usually have data apart from longer tunnels. Korea's KTX lines from Seoul to Busan and Gangneung are similar.
Away from the main lines, coverage is still good by world standards, but there are gaps. In Japan, mountain areas like the Japanese Alps around Kamikochi, the Tateyama Kurobe Alpine Route, the Kumano Kodo trails and the interior of Hokkaido have spots with weak or no signal. In Korea, Seoraksan and Jirisan national parks are well covered near trailheads but patchy deep in the valleys.
Islands vary too. Okinawa's main island and Jeju are well covered, but remote islands and ferry routes between them can have gaps. Download offline maps and trail details if you are heading into the mountains in either country.
Researched October 2026 · 4 sources
Twelve days in Japan and South Korea: Tokyo to Seoul via Kyoto, Hiroshima, Fukuoka and Busan
A rail-led route for first-time visitors that runs west across Japan by shinkansen, crosses the Korea Strait from Fukuoka to Busan by short flight or ferry, then heads north by KTX through Gyeongju to Seoul.
When to go Late March to mid-May and October to November bring mild weather, cherry blossom or autumn colour in both countries; July and August are hot and humid with typhoon risk that can cancel the Fukuoka–Busan ferries.
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Day 1 Tokyo
Tokyo: Asakusa, Ueno and Akihabara
Start at Senso-ji in Asakusa early, before the Nakamise shopping street fills up, then walk to the Sumida River for a view of the Tokyo Skytree. Take the Ginza line to Ueno Park and the Tokyo National Museum, and finish in Akihabara in the evening. Set up a transit IC card in your phone wallet on day one.
Signal Dense 4G and 5G on SoftBank or au; the Tokyo Metro has coverage in stations and most tunnels.
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Day 2 Tokyo
Tokyo: Meiji Jingu, Harajuku and Shibuya
Walk through the forest to Meiji Jingu, then down Takeshita Street and Omotesando. Continue to Shibuya for the scramble crossing and the view from Shibuya Sky, which needs a timed ticket. In the evening, go to Shinjuku for Omoide Yokocho and the free observation decks at the Tokyo Metropolitan Government Building.
Signal Excellent across Shibuya and Shinjuku, though the crowds at the scramble crossing can slow data at peak times.
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Day 3 Kyoto
Kyoto: Fushimi Inari and Higashiyama
Nozomi shinkansen from Tokyo to Kyoto, about 2 hours 15 minutes.
Take the Tokaido Shinkansen to Kyoto. Head straight to Fushimi Inari and walk up through the torii gates as far as the Yotsutsuji viewpoint. In the afternoon, walk from Kiyomizu-dera down Ninenzaka and Sannenzaka to Yasaka Shrine, ending in Gion around dusk.
Signal Good on the shinkansen with short drops in tunnels; full coverage in Kyoto, including the lower half of Fushimi Inari.
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Day 4 Kyoto
Kyoto: Arashiyama and Kinkaku-ji
Be at the Arashiyama bamboo grove soon after sunrise, then visit Tenryu-ji and cross the Togetsukyo bridge. Take a bus to Kinkaku-ji, the Golden Pavilion, and Ryoan-ji's rock garden next door. If you have energy left, Nishiki Market is good for an early dinner.
Signal Strong coverage throughout; Kyoto's buses get crowded, so live bus-arrival apps are worth having open.
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Day 5 Osaka
Nara day trip and Osaka evening
Kintetsu from Kyoto to Nara, about 45 minutes; Nara to Osaka Namba, about 40 minutes.
Take the Kintetsu line to Nara and walk from the station through the deer park to Todai-ji and its giant bronze Buddha, then up the lantern-lined paths to Kasuga Taisha. Move on to Osaka in the afternoon, check in near Namba, and spend the evening in Dotonbori under the neon signs and in the older Shinsekai district below Tsutenkaku tower.
Signal Full coverage in Nara Park and across central Osaka on SoftBank or au.
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Day 6 Hiroshima
Hiroshima and Miyajima
Shinkansen from Shin-Osaka to Hiroshima, about 1 hour 25 minutes; ferry to Miyajima, about 10 minutes.
Take the shinkansen to Hiroshima and spend the morning at the Peace Memorial Park, the Atomic Bomb Dome and the Peace Memorial Museum. In the afternoon, take the JR ferry from Miyajimaguchi to Miyajima for Itsukushima Shrine and its floating torii, and walk up towards Mount Misen if time allows.
Signal Good in Hiroshima and on the short ferry; the upper trails on Mount Misen are patchier.
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Day 7 Fukuoka
Fukuoka: Ohori Park and the yatai
Shinkansen from Hiroshima to Hakata, about 1 hour 5 minutes.
Continue west by shinkansen to Hakata. Visit Kushida Shrine, the guardian shrine of the old merchant town, and the Canal City complex nearby, then take the subway to Ohori Park for a walk round the lake and up to the ruins of Fukuoka Castle. In the evening, eat at the open-air yatai food stalls that set up along the river at Nakasu.
Signal Strong coverage in central Fukuoka; your last full day on a Japanese network, so download anything you need from Japanese apps tonight.
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Day 8 Busan
Across the strait to Busan
Flight Fukuoka to Busan, about 1 hour. Or a ferry from Hakata port: JR Kyushu's Queen Beetle no longer runs, but the Camellia Line and a hydrofoil service do; check current sailings.
Fly from Fukuoka to Busan Gimhae or take a ferry across the Korea Strait. In the afternoon, visit Gamcheon Culture Village on the hillside, then go down to Jagalchi Fish Market and BIFF Square in Nampo-dong. Install Naver Map or KakaoMap before arriving, as Google Maps still lacks walking directions in Korea.
Signal Offline for much of a ferry crossing. On arrival your phone switches to SK Telecom or LG Uplus, which can take a few minutes; toggle airplane mode if it does not.
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Day 9 Busan
Busan: Haeundae and Haedong Yonggungsa
Take the bus or a taxi to Haedong Yonggungsa, a temple on the rocks above the sea. Walk the coast to Haeundae Beach, then ride the Haeundae Blueline Park sky capsules along the old rail line towards Cheongsapo. In the evening, Gwangalli Beach has the best view of the lit-up Gwangan Bridge.
Signal Fast 5G across Haeundae and central Busan, including the subway.
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Day 10 Gyeongju
Gyeongju: tombs and temples
KTX from Busan to Gyeongju, about 30 minutes.
Take the KTX to Gyeongju, the capital of the old Silla kingdom. Walk among the royal burial mounds at Daereungwon, see the Cheomseongdae observatory and visit Donggung Palace and Wolji Pond at dusk, when it is lit. Bulguksa temple and the Seokguram grotto are a bus ride away and worth an early start.
Signal Good coverage in town and at Bulguksa; the forest road up to Seokguram has weaker spots.
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Day 11 Seoul
Seoul: palaces and Bukchon
KTX from Gyeongju to Seoul Station, about 2 hours.
Take the KTX to Seoul. Visit Gyeongbokgung Palace in time for the guard change, then walk through Bukchon Hanok Village and Samcheong-dong to Changdeokgung and its Secret Garden, which needs a timed tour. Finish in Insadong or at Gwangjang Market.
Signal Very strong 5G across central Seoul and on the KTX; the Seoul subway is fully covered.
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Day 12 Seoul
Seoul: Namsan, Myeongdong and the Han River
Take the cable car or walk up Namsan to N Seoul Tower for the view, then explore Myeongdong. In the afternoon, visit the National Museum of Korea or the War Memorial, and end with an evening along the Han River at Yeouido or the Banpo Bridge fountain. Allow about an hour on AREX to Incheon Airport.
Signal Excellent across the city and on the AREX line to Incheon.
Staying connected on this route
- Install Naver Map or KakaoMap before you fly to Korea; Google Maps works well in Japan but still lacks walking and driving directions in Korea.
- Save your ferry or flight booking and Busan arrival directions offline before leaving Fukuoka, as the Korea Strait crossing has no land signal.
- Turn on Japan's emergency alert settings in your phone so earthquake warnings reach you on a data-only eSIM.
Itinerary sources · 5
- en.wikivoyage.org Wikivoyage: Busan
- en.wikipedia.org Wikipedia: Beetle (JR Kyushu), Queen Beetle termination
- japan.travel Japan National Tourism Organization
- english.visitkorea.or.kr Korea Tourism Organization: VisitKorea
- gov.uk GOV.UK: Foreign travel advice, South Korea
Information and verification
Each block below says what was checked and when. Anything we cannot date, we do not claim.
- Prices and plans
- Every price and allowance on this page is read from the live catalog, not typed in.
Japan & South Korea eSIM prices
| Data | Price | Per day |
|---|---|---|
| Unlimited | $11.99 | $4.00/day |
| Data | Price | Per day |
|---|---|---|
| Unlimited | $18.99 | $3.80/day |
| Data | Price | Per day |
|---|---|---|
| Unlimited | $34.99 | $3.50/day |
| Data | Price | Per day |
|---|---|---|
| 3 GBBest value | $7.00 | $0.23/day |
| 5 GB | $9.99 | $0.33/day |
| 10 GB | $18.99 | $0.63/day |
| 20 GB | $31.00 | $1.03/day |
| Unlimited | $93.00 | $3.10/day |
| Data | Price | Per day |
|---|---|---|
| Unlimited | $189.99 | $3.17/day |
| Data | Price | Per day |
|---|---|---|
| Unlimited | $284.99 | $3.17/day |
| Data | Price | Per day |
|---|---|---|
| Unlimited | $559.99 | $3.11/day |
Destinations
