In This Article
In partnership with Ubigi. Our research, ratings, and the pros and cons below are our own.
You have been planning this Japan trip for months. You have your itinerary, your rail pass, even the konbini snacks you want to try. But the second your flight lands at Narita, one quiet thing can make or break the first hour, the first day, and honestly the whole trip: your phone connection.
Japan runs fast 5G across its cities and even along the Shinkansen, yet getting online as a visitor is trickier than you would expect. Roaming is expensive, public Wi-Fi is patchy, and swapping a physical SIM at the airport is the last thing you want after a long flight. An eSIM fixes that. The catch is that the dozens of providers are not built the same. Some keep you connected from Tokyo to rural Takayama; others quit right when you need them. Here are the seven best, ranked on real-world use.
How we ranked these. We compared each eSIM on the things that decide a Japan trip: which Japanese carrier it actually rides, real 5G availability, tethering, the fair-use small print behind every “unlimited” plan, and price per gigabyte. Our research draws on each provider’s own plan pages, independent testing, and traveller reports, cross-checked against primary sources.
Quick comparison: the 7 best Japan eSIMs
| Provider | Japan network | Start price | 5G | Tethering | Unlimited (fair use) |
|---|---|---|---|---|---|
| Ubigi | NTT Docomo + KDDI (au) | $3.50 (1GB, 3 days) | Yes, real 5G | Yes, unrestricted | Yes, fair use (25 to 60GB then 2 Mbps) |
| Airalo | KDDI (au) + SoftBank | $4.00 (1GB, 3 days) | Mostly 4G in practice | Yes | Yes, 3GB per day then 1 Mbps |
| Saily | Docomo + SoftBank (multi, opaque) | $3.99 (1GB, 7 days) | Not clearly confirmed | Yes, unrestricted | Yes, daily allowance then throttle |
| MobiMatter | Varies by plan (marketplace) | $4.49 (3GB, 5 days) | 4G/5G, plan dependent | Yes | No unlimited, fixed data only |
| Jetpac | Multi-network, KDDI primary | $5.00 (3GB, 1 day) | 4G/5G, not guaranteed | Yes, unrestricted | Yes, 3GB per day then 1 Mbps |
| Matcha | Docomo + KDDI (au) | $1.60 (1GB, 1 day, with code) | 4G/5G, not guaranteed | Likely, unconfirmed | Yes, 3GB per day then 128 kbps |
| Nomad | Undisclosed (KDDI/SoftBank) | $4.00 (1GB, 7 days) | 4G/5G, not guaranteed | Yes | Yes, 2GB per day then 1 Mbps |
One honest note up front: none of these plans are truly unlimited. Every “unlimited” option is fair-use, full speed up to a cap or a daily allowance, then a throttle. The table shows where each one lands.
Why the carrier network matters more than the price
Japan has three networks that matter: NTT Docomo, KDDI (au), and SoftBank. In the cities they are close enough that you will not notice the difference. The gap opens up in the countryside, on mountain routes, remote islands, and rural rail lines, and there Docomo is the consensus leader, with KDDI close behind and SoftBank the weakest of the three.
So the single most useful question is not “how cheap is it” but “which carrier does it ride.” An eSIM that includes Docomo is the safer bet for Hokkaido, the Hida mountains, or Takayama. That is the honest reason Ubigi leads this list: it is the only option here on both Docomo and KDDI with working 5G. Worth knowing too, Japanese carriers have mostly not extended 5G to travel-eSIM traffic, so a provider that delivers real 5G is the exception, not the rule.
| Network | City coverage | Rural and mountain | eSIMs here that use it |
|---|---|---|---|
| NTT Docomo | Excellent | Best of the three | Ubigi, Matcha, Saily |
| KDDI (au) | Excellent | Strong, close behind | Ubigi, Airalo, Matcha |
| SoftBank | Excellent | Weakest of the three | Airalo, Saily |
1. Ubigi
Ubigi is a full MVNO (Mobile Virtual Network Operator) network operator backed by Transatel, part of the NTT group, not a reseller, and that shows in Japan. Your phone rides both NTT Docomo and KDDI, the two strongest networks for rural and mountain coverage, and switches to whichever is stronger automatically. It is the only eSIM in this roundup on both of those carriers with working 5G, which is why it tops the list.
SmartStart means the plan starts when you land, not when you buy, so you can set it up weeks ahead and waste no days in transit. Tethering is unrestricted, and you can top up in the app even with no data left.
| Validity | Data | Price (USD) |
|---|---|---|
| 3 days | 1GB | $3.50 |
| 7 days | 10GB | $14 |
| 7 days | Unlimited (fair use) | $25 |
| 15 days | Unlimited (fair use) | $39 |
Best for: Best overall, and the safest pick for rural Japan.
Pros
- The only pick on both NTT Docomo and KDDI, so it holds a signal in the countryside where single-carrier eSIMs drop out.
- Genuine 5G included at no extra cost, plus unrestricted tethering.
- SmartStart deferred activation and in-app top-ups without Wi-Fi.
Cons
- The priciest per gigabyte on the smallest plans. But great value on the more popular plans from 10GB and up.
- Unlimited is fair-use: full speed to a 25 to 60GB cap, then 2 Mbps.
- 2 Mbps is the fastest post-FUP speed in the market, and the policy is very transparent which is a plus.
- Support can be slow at times, although with the optimized AI chatbot (called Ubi) and the new 24/7 team of live agents, your questions are likely to be answered.
Get it: 🌐 Visit Website · 📱 Download App for Android · 🍎 Download App for iOS
2. Airalo
Airalo is the most familiar name in travel eSIMs, and its Moshi Moshi plan for Japan has the cleanest app and the smoothest purchase-to-activation flow in this group. In cities it is fast and reliable, and the per-gigabyte price on small plans is keen.
The trade-off is the network. Airalo rides KDDI and SoftBank, not Docomo, so it is the weaker choice once you leave the big cities, and in practice most users sit on 4G rather than 5G.
| Validity | Data | Price (USD) |
|---|---|---|
| 3 days | 1GB | $4.00 |
| 30 days | 20GB | about $26 |
| Daily | Unlimited (3GB/day) | from about $6/day |
Best for: Best app and smoothest setup for city trips.
Pros
- The slickest app and onboarding of the seven.
- Cheap, reliable data in Tokyo, Osaka, and other cities.
- Huge global brand if you reuse it beyond Japan.
Cons
- No Docomo, so rural and mountain reach is weaker than Ubigi.
- Effectively 4G for most users despite a 5G badge.
- Unlimited is a 3GB daily cap, then a slow 1 Mbps.
Get it: 🌐 Visit Website · 📱 Download App for Android · 🍎 Download App for iOS
3. Saily
Saily comes from the team behind NordVPN, and it brings privacy tools most eSIMs do not: ad blocking, web protection, and a virtual-location feature. Tethering is genuinely unrestricted, with no separate hotspot cap, which makes it a strong sharing option.
The catch is that the carrier story is opaque. Saily switches between networks reported as Docomo and SoftBank, so you do not always know which one you are on, and reliable 5G is not confirmed for Japan.
| Validity | Data | Price (USD) |
|---|---|---|
| 7 days | 1GB | $3.99 |
| 30 days | 10GB | about $19 |
| Daily | Unlimited (fair use) | from about $5/day |
Best for: Best for privacy extras and generous tethering.
Pros
- Built-in ad blocking, web protection, and virtual location.
- Unrestricted tethering with no hotspot cap.
- Trusted Nord Security brand behind it.
Cons
- You cannot reliably tell which carrier you are connected to.
- 5G in Japan is not confirmed, so treat it as a 4G option.
- Account and plans live behind its own app.
Get it: 🌐 Visit Website · 📱 Download App for Android · 🍎 Download App for iOS
4. MobiMatter
MobiMatter is a marketplace that resells several underlying eSIM products, so the headline is value, not a single network. Its 50GB 30-day plan works out near $0.60 per gigabyte, among the cheapest in this group for anyone who burns through data.
Because it is a marketplace, the carrier and 5G availability depend on the exact plan you buy, and there is no true unlimited option, only large fixed buckets.
| Validity | Data | Price (USD) |
|---|---|---|
| 5 days | 3GB | $4.49 |
| 30 days | 50GB | about $30 |
| 90 days | 60GB | about $34 |
Best for: Best value per gigabyte for heavy data users.
Pros
- Lowest cost per gigabyte for heavy users.
- Large buckets with long validity windows.
- Tethering supported across plans.
Cons
- No unlimited option at all.
- Carrier and 5G depend on the specific plan, so no Docomo guarantee.
- Quality varies by the underlying product you pick.
Get it: 🌐 Visit Website · 📱 Download App for Android · 🍎 Download App for iOS
5. Jetpac
Jetpac leans on aggressive pricing and frequent discount codes, often around 15 percent off, and its fixed-data plans run at full speed for the whole validity window. Tethering is unrestricted, which is a plus for sharing on the go.
The carrier story is mixed and not clearly stated, and reliable 5G via its network arrangement is not proven, so treat it as a value play rather than a coverage play.
| Validity | Data | Price (USD) |
|---|---|---|
| 1 day | 3GB | $5.00 |
| 7 days | 15GB | about $15 |
| 30 days | 30GB | about $30 |
Best for: Best for discount-hunters on short trips.
Pros
- Aggressive pricing with frequent promo codes.
- Unrestricted tethering.
- Full speed for the whole validity on fixed plans.
Cons
- Carrier mix is unclear, so rural reach is uncertain.
- Unlimited is a 3GB daily cap, then 1 Mbps.
- 5G is not reliably proven.
Get it: 🌐 Visit Website · 📱 Download App for Android · 🍎 Download App for iOS
6. Matcha
Matcha is aimed at Japan travellers and rides Docomo and KDDI through an underlying provider, so its carrier base is genuinely good for rural reach. With its standing discount code the 1-day 1GB plan can drop to about $1.60, the lowest entry price here.
The downside is the harshest throttle in the group. Once you pass the 3GB daily allowance on an unlimited plan, the speed drops to 128 kbps, which is close to unusable, and tethering is not clearly confirmed.
| Validity | Data | Price (USD) |
|---|---|---|
| 1 day | 1GB | $1.60 (with code) |
| 5 days | 10GB | about $14 |
| 10 days | 20GB | about $24 |
Best for: Cheapest entry price for a quick top-up.
Pros
- Lowest promotional entry price of the seven.
- Rides Docomo and KDDI, so the carrier base is strong.
- Familiar travel brand for Japan visitors.
Cons
- Harshest throttle after the cap, down to 128 kbps.
- Tethering is not clearly confirmed.
- Reseller, so 5G and support depend on the upstream provider.
Get it: 🌐 Visit Website
7. Nomad
Nomad has a clean app and unusually long validity on its larger plans, with 45-day windows that suit slow or extended trips. Mid-size plans are competitively priced and discount codes show up often.
Nomad does not disclose its Japanese carrier, and its unlimited plan gives the smallest daily full-speed allowance in this group at 2GB, so it is a steady mid-tier choice rather than a coverage leader.
| Validity | Data | Price (USD) |
|---|---|---|
| 7 days | 1GB | $4.00 |
| 30 days | 10GB | about $19 |
| 45 days | 50GB | about $39 |
Best for: Best for slow, long trips on big buckets.
Pros
- Clean, easy app.
- Long 45-day validity on big buckets for extended trips.
- Competitive mid-size plans with frequent promo codes.
Cons
- Carrier is undisclosed, so no rural guarantee.
- Unlimited gives only 2GB per day before throttling.
- 5G is not guaranteed.
Get it: 🌐 Visit Website · 📱 Download App for Android · 🍎 Download App for iOS
How much data do you actually need in Japan?
Most travellers overbuy. Maps, messaging, translation, train apps, and mobile payments are light; video and tethering are what eat data. As a rough guide for a typical trip:
| Trip length | Light use (maps, chat, IC pay) | Heavy use (video, tethering) |
|---|---|---|
| 3 to 5 days | 3 to 5GB | 10 to 15GB |
| 1 week | 5 to 10GB | 20GB or unlimited |
| 2 weeks or more | 10 to 20GB | Unlimited (fair use) |
How to install and set up your Japan eSIM
Set it up at home on Wi-Fi before you fly, so you can confirm it works. Your phone must support eSIM and be network-unlocked.
On Android
- Buy a plan and get the QR code by email.
- Open Settings, Network and internet, SIMs, then Add eSIM and scan the code.
- Label it for Japan, and set it as your default for mobile data while keeping your home SIM for calls and texts.
On iPhone
- Buy a plan and get the QR code by email.
- Open Settings, Cellular, Add eSIM, and scan the code.
- Label it, then set it as your default line for data only.
FAQs about eSIMs for Japan
Short on time? The quick answers below cover roaming versus eSIM, using two SIMs at once, rural coverage, tethering, 5G, and how much data a Japan trip really needs.
Do I need an eSIM, or can I just use roaming?
An eSIM is almost always cheaper and faster to set up than home-carrier roaming, and you keep your normal number active for calls and texts. Roaming makes sense only for a very short stopover.
Can I use an eSIM and my regular SIM at the same time?
Yes. On a dual-SIM phone you keep your physical SIM for calls and texts and use the eSIM for data. That is the setup we recommend.
Which eSIM has the best coverage in rural Japan?
One that rides NTT Docomo. Ubigi (Docomo plus KDDI) is the safest pick here for mountains, remote islands, and rural rail; Matcha also uses Docomo and KDDI.
When should I activate my Japan eSIM?
Install it before you fly, but most plans only start counting when you connect in Japan. Ubigi’s SmartStart does this automatically, so you can buy weeks ahead.
Do Japan eSIMs support tethering?
Most do. Ubigi, Saily, and Jetpac allow unrestricted tethering; on fair-use unlimited plans, heavy tethering burns the full-speed allowance faster.
Can I make phone calls with a Japan eSIM?
Not native calls or texts; these are data-only and give no phone number. Use WhatsApp, LINE, or FaceTime over the data connection, or keep your home SIM active for calls.
How much data do I actually need?
For light use, plan on roughly 1 to 2GB per day. Maps, translation, and mobile payments are light; streaming and tethering are what add up.
Is 5G available in Japan with a travel eSIM?
Sometimes. Japanese carriers have mostly not extended 5G to travel-eSIM traffic, so real 5G on an eSIM is the exception. Ubigi is one of the few that reliably delivers it.
What happens if I run out of data?
You buy a top-up in the provider’s app. With Ubigi this works even with no Wi-Fi and no data left, so you are not stranded.
The bottom line
If you want one pick and you are done reading, choose Ubigi. It is the only eSIM in this roundup on both NTT Docomo and KDDI with real 5G and unrestricted tethering, which makes it the safest choice whether you stay in Tokyo or head for the mountains, and SmartStart means it just works when you land. See current Ubigi Japan plans.
If price is your only concern, Ubigi can be a bit more expensive than bargain options depending on your plan of choice. Matcha has the lowest entry price, MobiMatter the cheapest data per gigabyte, and Airalo the smoothest app for a city-only trip. Match the eSIM to your trip, and you will not waste that first hour in Japan hunting for a signal.
