When traveling in Japan, you’ll probably use your phone more often than you expect — checking Google Maps, looking up train routes, translating a menu, or finding your hotel.
Free Wi-Fi is available at some stations, hotels, and other public places, but connecting isn’t always straightforward, and speed or security can sometimes be a concern.
Think of free Wi-Fi as a useful backup, not something you should have to rely on throughout your trip.
In this guide, we compare five popular eSIM options for Japan based not only on price, but also on the networks they use in Japan, data allowance, ease of use, and how well they fit different travel styles.
Affiliate disclosure: Some links on this page are affiliate links. If you make a purchase through them, Project Torii may earn a commission at no extra cost to you. This does not affect our recommendations.
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People in Japan are often happy to help — and staying connected makes it easier
If you get lost in Japan and ask someone nearby or speak to a station attendant, you’ll often find someone willing to help.
At the same time, many people in Japan aren’t confident speaking English. Sometimes, someone may want to help but not feel comfortable explaining things in English.
That becomes much easier when your phone is connected.
You can show them a question in a translation app. Point to your destination on Google Maps. Show your hotel reservation, an address, or a photo of the restaurant you’re looking for.
You don’t need perfect English — and you certainly don’t need perfect Japanese.
Internet access in Japan isn’t just about convenience. It can also be one of the easiest ways to bridge the language gap.
That’s why Project Torii looks beyond headline download speeds when evaluating eSIMs. What matters is having a connection that works well for the places and situations you’re likely to encounter during your trip.
30-Second Finder: Which Japan eSIM Is Right for You?
Start with three questions.
Q1. How long will you be in Japan?
1–7 days / 8–14 days / 15+ days
Q2. What will you mainly use your phone for?
Maps and translation / Maps plus social media / Heavy video use or tethering
Q3. Where are you traveling?
Major cities / Cities and regional areas / Rural areas and nature
Find the travel style closest to yours
1–14 days, mainly maps and translation, mostly major cities
Our pick: Ubigi
A well-balanced choice for a first trip to Japan, with reasonable pricing, access to two major Japanese networks, and a straightforward setup.
→ Check Ubigi’s current Japan plans
Alternative: Nomad — Worth comparing if price matters more to you.
1–14 days, with frequent social media use
Our pick: Nomad
A strong balance of price and data allowance, with options for travelers who expect to use 10GB or more.
Alternative: Ubigi — A good alternative if simplicity and ease of use matter more.
→ Is 10GB enough? See how much data you need for a trip to Japan
15 days or longer
Our pick: Nomad
Its 10GB, 20GB, and 50GB fixed-data plans make it easy to choose an allowance for a longer trip.
Alternative: Ubigi — Its 30-day plans and easy top-ups also make it worth considering.
→ How much data do you need for a trip to Japan?
You watch a lot of video
Our pick: Holafly
A good fit for travelers who want to use plenty of data directly on their phone without constantly checking how much is left.
Alternative: Airalo or Ubigi — Compare their high-speed data thresholds before choosing an unlimited plan.
→ Do you really need unlimited data? See how much data video streaming and social media can use
You tether your laptop frequently
Our pick: Airalo
Airalo permits hotspot use without a separate tethering cap or a provider-imposed device limit on its unlimited plans. All use, including tethering, counts toward the same daily high-speed allowance.
Its unlimited plans currently provide 3GB of high-speed data per 24-hour period, after which speeds are reduced to 1 Mbps until the next reset.
Alternative: Nomad — Compare its 50GB fixed plan with Unlimited; frequent tethering can use the 2GB daily high-speed allowance quickly.
You’ll spend a lot of time in regional or rural Japan
Our pick: Ubigi
In Japan, Ubigi can connect to KDDI and NTT Docomo networks.
→ Check Ubigi’s current Japan plans
Alternative: Nomad — Its current Japan page lists KDDI au and SoftBank, but the exact network configuration can vary by plan.
→ docomo vs KDDI vs SoftBank: Which Japanese mobile network is best for travelers?
This recommendation is based on published partner-network information, not side-by-side testing of all five services across Japan. Real-world performance can also vary by plan, location, congestion, device, and roaming configuration.
You also care about security and privacy features
Our pick: Saily
Saily includes additional features such as Web Protection, Ad Blocker, and Virtual Location.
→ Check Saily’s current Japan plans — get 10% off
10% off for Project Torii readers: The discount is applied automatically through this link. If needed, enter code PROJECTTORII at checkout.
Alternative: Ubigi / Nomad — Better choices if your priority is a straightforward mobile data plan without extra security tools.
Compare Before You Buy: 5 eSIMs for Japan
Project Torii doesn’t simply rank these eSIMs from #1 to #5.
There isn’t one “best” eSIM for everyone. The goal is to find the one that best fits your trip.
What does Travel Match mean?
● Strong Choice
A solid option for a broad range of travelers, including first-time visitors to Japan.
● Good for the Right Traveler
Potentially an excellent choice, but its value depends more heavily on how you travel and use your phone.
● Specialized Choice
Not necessarily a bad service — simply one that makes the most sense for travelers with a specific need or travel style.
| eSIM | Reference Plan | Validity | Japan Network / Key Feature | Travel Match |
|---|---|---|---|---|
| Ubigi | 10GB $16.50 | 30 days | KDDI / NTT Docomo; fixed + unlimited | ● |
| Nomad | 10GB $16 | 30 days | KDDI au / SoftBank*; fixed + unlimited | ● |
| Airalo | 10GB $18 | 30 days | Fixed-data + unlimited options | ● |
| Saily | 10GB $17.99 | 30 days | Security tools + unlimited | ● |
| Holafly | Unlimited | By number of days | KDDI / SoftBank; unlimited only | ● |
Product information was re-checked on August 8, 2026. Prices and plan details can vary by currency, region, promotion, and checkout view, so confirm the exact network, fair-use terms, and final price before purchasing.
*Nomad’s current Japan page lists KDDI au and SoftBank, but network configurations can vary by plan. Treat the exact Network and Plan Details at checkout as authoritative.
→ docomo vs KDDI vs SoftBank: Which Japanese mobile network is best for travelers?
→ 10GB, 20GB or Unlimited: How much data do you actually need in Japan?
“Unlimited” doesn’t mean the same thing with every provider
This is one of the most important details to check before you buy.
| Provider | Key Unlimited Conditions |
|---|---|
| Ubigi | 7-day plan: 25GB at full speed; 15-day: 30GB; 30-day: 60GB. Then 2 Mbps for the rest of the plan. |
| Nomad | 2GB of high-speed data per 24-hour window, then 512 kbps until the next reset. |
| Airalo | 3GB of high-speed data per 24-hour period, then 1 Mbps until the next reset. Hotspot use shares this allowance; no separate tethering cap. |
| Saily | 5GB of high-speed data per 24-hour period, then up to 1 Mbps until the next reset. |
| Holafly | No strict daily data cap, but a local-network Fair Usage Policy may temporarily reduce speeds for up to one day. Hotspot sharing: 1GB per day. |
In other words, do not compare plans based on the word “Unlimited” alone.
The key question is whether you want to stream video, tether a laptop, or simply stop tracking your remaining data.
The right unlimited plan depends on how you actually intend to use it.
→ Do you really need Unlimited data in Japan?
A Closer Look at Each eSIM
Ubigi: A strong all-round choice for a first trip to Japan
Travel Match: ● Strong Choice
Ubigi’s main strength is its balance of price, access to KDDI and NTT Docomo, and ease of use.
Its 10GB/30-day plan costs US$16.50. Ubigi also offers unlimited plans that cover Japan for 7, 15, and 30 days; the current options list KDDI and NTT Docomo.
→ docomo vs KDDI vs SoftBank: Which Japanese mobile network is best for travelers?
You can install the eSIM before your trip, and Smartstart begins the plan when the eSIM first connects at your destination. The same eSIM profile can be reused in supported destinations, and Ubigi supports both top-ups and data sharing.
Good fit for: First-time visitors / Maps, translation, and social media / Travelers looking for balance
Not for you if: You need unlimited full-speed data with no fair-use threshold
→ Check Ubigi’s current Japan plans
Nomad: Strong value for travelers who need more data
Travel Match: ● Strong Choice
Nomad’s 10GB/30-day plan costs US$16. Its 20GB plan costs US$23, while its 50GB plan costs US$35.
→ Is 10GB enough? See how much data you need for a trip to Japan
Nomad’s current Japan page lists KDDI au and SoftBank. Because network configurations can vary by plan, check the Network and Plan Details for the exact plan at checkout.
→ KDDI vs SoftBank: What’s the difference for travelers in Japan?
You can install the eSIM before traveling. In most cases, the plan activates when it first connects to a supported network in Japan. Some eSIMs may require manual activation, however, so check the instructions provided with your purchase.
Good fit for: Value-conscious travelers / Frequent social media use / Travelers expecting to use 10GB or more
Not for you if: You prefer the fewest possible plan choices and the simplest setup
Airalo: For travelers who want more plan choices
Travel Match: ● Strong Choice
Airalo’s 10GB/30-day Japan plan costs US$18.
It offers both fixed-data and Unlimited options, giving you more flexibility to match the plan to the way you use your phone.
→ 10GB, 20GB or Unlimited: Which should you choose?
Its unlimited plans currently provide 3GB of high-speed data per 24-hour period, after which speeds are reduced to 1 Mbps until the next reset. Airalo allows hotspot use without a separate tethering cap or a provider-imposed device limit, but hotspot use shares the same daily allowance.
Good fit for: Travelers who value choice / Travelers comparing unlimited plans / Travelers who tether other devices
Not for you if: You prefer fewer, simpler plan choices
Holafly: For travelers who don’t want to think about remaining data
Travel Match: ● Good for the Right Traveler
Holafly’s main selling point is unlimited data for use on your phone.
In Japan, it uses KDDI and SoftBank networks.
→ KDDI vs SoftBank: What’s the difference for travelers in Japan?
Holafly does not set a strict daily data cap, although a local-network Fair Usage Policy may temporarily reduce speeds for up to one day. Its Japan plan allows 1GB of data sharing per day with other devices.
That makes Holafly attractive for travelers who use a lot of data directly on their phone, but less suitable if you plan to tether a laptop heavily.
→ Do you really need Unlimited data in Japan?
Good fit for: Heavy phone data use / Travelers who do not want to track a data balance
Not for you if: Price is your main priority / You need heavy laptop tethering
→ Read our full Holafly review
Saily: For travelers who also value security features
Travel Match: ● Good for the Right Traveler
Saily’s 10GB/30-day plan costs US$17.99, while its 20GB/30-day plan costs US$24.99.
Its 15-day unlimited plan costs US$48.99. It includes 5GB of high-speed data per 24-hour period; speeds are then capped at up to 1 Mbps until the next reset.
→ 10GB, 20GB or Unlimited: Which should you choose?
Saily also includes features such as Web Protection, Ad Blocker, and Virtual Location.
Its Web Protection and Ad Blocker are DNS-based. They can filter malicious domains, trackers, and many ads, but they do not protect against every online threat.
Good fit for: Travelers who also value security and privacy features
Not for you if: You simply want mobile data without additional features
→ Check Saily’s current Japan plans — get 10% off
10% off for Project Torii readers: The discount is applied automatically through this link. If needed, enter code PROJECTTORII at checkout.
Project Torii’s Verdict
If you’re still unsure, here’s the simplest way to think about it:
First trip to Japan and want an easy all-round choice → Ubigi
Want a strong balance of price and data allowance → Nomad
Want more plan choices or expect to tether → Airalo
Want unlimited phone data without tracking a balance → Holafly
Want built-in browsing security and privacy tools → Saily
There is no single eSIM that is “best” for every traveler.
What matters is how long you’ll be in Japan, where you’re going, and how you’ll actually use your phone.
If you’re still undecided, go back to the 30-Second Finder and check both the recommended option and the alternative for your travel style.
Once you’ve narrowed it down to two choices, our head-to-head comparisons can help you make the final decision.
Compare the eSIMs side by side
Want to Know More?
Understanding Japan’s mobile networks
Travel eSIMs in Japan commonly connect through networks operated by NTT Docomo, KDDI au, and SoftBank.
If you’re only visiting major destinations such as Tokyo, Kyoto, and Osaka, you probably don’t need to overthink the network choice.
But if you will travel beyond the major cities or spend more time in rural and natural areas, the partner networks available on each plan become more relevant.
→ docomo vs KDDI vs SoftBank: Which Japanese mobile network is best for travelers?
How much data do you need in Japan?
For a typical 7- to 14-day trip, Project Torii recommends using around 10GB as a practical starting point.
You may need less if you mainly use maps, translation, and messaging. But frequent use of Instagram, TikTok, YouTube, and other video-heavy apps can increase your data usage significantly.
→ How much data do Instagram, TikTok, and YouTube use? Choosing the right data allowance for Japan
Before You Go: Final Checks Before Buying an eSIM
1. Make sure your phone supports eSIM
Not every smartphone supports eSIM.
Support can also vary between versions of the same model sold in different countries or regions.
Before purchasing, check your eSIM provider’s compatibility list and confirm your exact phone model.
2. Check that your phone is unlocked
Even if your phone supports eSIM, a carrier-locked device may prevent you from using a travel eSIM.
Make sure your phone is unlocked before purchasing.
3. Don’t confuse installation with activation
After purchasing an eSIM, you will usually add it to your phone using a QR code, direct app installation, or manual details provided by the eSIM company.
In this context, the QR code contains the information your phone needs to add the eSIM profile.
But installing an eSIM does not necessarily mean the validity period starts immediately.
Check the provider’s instructions to confirm when you should install the eSIM and when the plan actually activates.
4. Check your mobile data settings after arriving in Japan
Some travel eSIMs require data roaming to be switched on.
At the same time, allowing your regular SIM to use mobile data overseas may result in roaming charges depending on your home carrier and plan.
Before using your phone in Japan, confirm which SIM is selected for mobile data.
FAQ: Using an eSIM in Japan
Do I need an eSIM to travel in Japan?
No.
International roaming, physical SIM cards, and pocket Wi-Fi are also available.
→ Compare eSIM vs pocket Wi-Fi in Japan
But if your phone supports eSIM, it can be a convenient option because there’s nothing to pick up or return, and you can get connected soon after arriving in Japan.
Do I need to buy an eSIM at a Japanese airport?
Usually, no.
If your chosen provider sells eSIMs online, you can buy it before leaving for Japan; follow the provider’s guidance on when to install and activate it.
Will my Japan eSIM give me a Japanese phone number?
Most Japan plans compared in this guide are primarily data plans and do not include a Japanese phone number.
If you need a Japanese phone number, voice calls over the mobile network, or SMS, check the exact features of the plan before purchasing.
Internet-based services such as WhatsApp, LINE, and FaceTime can still work over your data connection.
Can I use my regular SIM and a travel eSIM at the same time?
Often, yes — if your phone supports dual SIM.
For example:
Regular SIM → Calls and SMS
Travel eSIM → Mobile data in Japan
Exact dual-SIM functionality depends on your device.
Will an eSIM work everywhere in Japan?
No.
Coverage may be unavailable in some mountainous areas, tunnels, remote islands, and other locations.
Even in cities, coverage and speeds can vary with congestion, station layout, tunnels, and the rail route you take.
→ docomo vs KDDI vs SoftBank: Which Japanese mobile network is best for travelers?
Should I choose 5GB, 10GB, 20GB, or Unlimited?
For a typical 7- to 14-day trip, around 10GB is a useful starting point.
You may need less if you mainly use maps, translation, and messaging.
If you use social media and video frequently, consider 20GB or an unlimited plan — after checking its full-speed and tethering limits.
→ How much data do Instagram, TikTok, and YouTube use? Choosing the right data allowance for Japan
Does Unlimited really mean there are no limits?
Not necessarily.
Providers differ in their high-speed allowances, reset windows, post-threshold speeds, and hotspot limits.
Do not choose based on the word “Unlimited” alone; check the plan’s fair-use and hotspot terms.
Sort out your connection before you leave — then spend your time in Japan enjoying the trip itself.