Traveling to Japan can be thrilling, but staying connected while exploring cities like Tokyo and translating Japanese signs or restaurant menus can be a challenge. That’s where Ubigi comes in. With their digital SIM, you can skip the airport SIM card queues, avoid expensive roaming fees, and have reliable data ready the moment you land. Whether you’re checking train schedules, navigating winding streets, or sharing photos of your adventures, Ubigi eSIM Japan plans ensures you stay online seamlessly. In this guide, we’ll explore setup, coverage, real world performance, and whether Ubigi is the best choice for your Japanese adventure.
How eSIMs Work: A Simple Explanation for Travelers
If you’ve ever struggled with swapping SIM cards while traveling, an eSIM can feel like a game-changer. Short for “embedded SIM,” an eSIM is a small digital chip built directly into your smartphone, tablet, or other compatible device. Unlike traditional SIM cards, you don’t physically remove or insert anything — all the necessary information to connect to a mobile network is stored digitally.
Once you activate an eSIM plan, your device connects automatically to the chosen network. Switching carriers or data plans is just a few taps away, meaning you can travel to Japan without juggling multiple physical SIMs. This means instant connectivity upon arrival, fewer headaches at airports, and more time to enjoy your trip.
An introduction to Ubigi eSIMs in Japan
Launched in 2017 by Transatel, a French company that became part of NTT (the Japanese telecom giant) in 2019, Ubigi has become a top name in the world of eSIMs. They focus on keeping travelers and remote workers connected, offering reliable mobile data in over 200 destinations around the globe.
If you’re heading to Japan, Ubigi brings their connection expertise straight to your phone. Thanks to partnerships with local networks, you can enjoy fast, reliable data as soon as you land. All it takes is a few taps to pick a plan that fits your trip, activate it on your device, and get online with no physical SIM card required. It’s simple and convenient for staying connected while exploring everything Japan has to offer.
Key Features of Ubigi eSIMs
Ubigi provides smartphone data plans for travelers who want convenience, reliability, and flexibility. Here’s what makes it stand out:
Strong and Reliable Coverage
Ubigi eSIM Japan works with top carriers like KDDI (au) and NTT Docomo, giving you solid coverage in all major destinations such as Tokyo, Osaka, and Kyoto. Even in many suburban or rural areas, you can expect stable connectivity, so your maps and apps will keep working wherever you go.
Flexible Data Options
No two trips are the same, which is why Ubigi offers plans for every type of traveler. Choose from one-off to monthly and annual packages, with data allowances that range from a few gigabytes for light browsing to larger unlimited plans suitable for streaming and social media.
Easy Setup Through the App
Setting up your eSIM is quick and straightforward. Simply download the Ubigi app, register your account, select a plan, and then activate. The process works on both iOS and Android devices, so you can be online in minutes.
Share Your Connection with Hotspot
Need to connect a laptop, tablet, or other devices? Ubigi eSIM Japan plans supports tethering, making it easy to share your data on the go — perfect for when you need a larger screen, or keeping friends and family online while exploring.
Affordable Travel Data
Compared to international roaming, Ubigi eSIM Japan plans are cost-effective and designed to match your actual usage. You can pick a plan that fits your trip, and avoiding overpaying for unused data while still staying fully connected.
Helpful Customer Support
Ubigi offers assistance through swift email support and have a livechat option. Whether you run into trouble activating your eSIM or need guidance while using it in Japan, support is there to help you efficiently — when we tried to contact customer support on Sunday afternoon we received an automated AI response to a general question within 1 minute. You then get a choice to get further team support, and when we requested this, we had a full response from one of the team 7 minutes later.
How to Get and Activate Ubigi eSIM in Japan
Step 1: Check Your Phone Compatibility
Most smartphones released in the past few years already support eSIM, but it’s always a good idea to double-check. Ubigi provides a full list of compatible iPhones, Android devices, and even laptops on their website. Just make sure your phone is unlocked and not tied to a specific carrier before making an eSIM purchase.
Step 2: Choose a Ubigi eSIM Japan Plan
Open the Ubigi app and browse plans for Japan. For short trips, 10GB for 7 days is ideal and costs $14 USD; longer trips may require 10–20GB or more, in which case you may want to consider an Unlimited plan for 15 days for $39 USD, or 25GB for 30 days that costs $32 USD.
Step 3: Install and Activate Your Ubigi eSIM for Japan
- Download the Ubigi app from the App Store or Google Play.
- Signup and register your email then verify your email.
- Purchase your Ubigi eSIM Japan plan and access your eSIM details. Or puchase your eSIM on the web first here and install the app after.
- Go to your phone’s mobile settings and add a new eSIM. Note that you will need to scan a QR code to activate if you purchase from the Ubigi website instead of purchasing on the app.
- Turn on the Ubigi line, enable data roaming, and double-check network selection. Sometimes manual network selection is necessary.
After being activated, your Ubigi eSIM should connect automatically once you are in your data plan’s destination country. A restart or airplane mode toggle usually fixes minor glitches.
Ubigi eSIM Japan Performance
Speed and Coverage
- Urban areas (Tokyo, Osaka, Kyoto): Fast speeds which are perfect for browsing, streaming, and video calls.
- Rural or indoor areas: Speeds may drop in more remote locations especially indoors in country areas.
Ubigi eSIM Japan plans generally perform best in city centers and even underground in Tokyo or at the airport. However, performance may vary in countryside locations for all networks especially inside buildings or in hilly areas.
To illustrate the speed and performance of Ubigi eSIM in Japan, we created the above video which looks at how Ubigi performed when we tested it out in Osaka, Nagoya and Tokyo. We also checked the speed of Ubigi in a remote area — from the summit of Mount Misen on Itsukushima (Miyajima Island) in Hiroshima Bay.
Pros and Cons of Ubigi eSIM in Japan
Pros of Ubigi eSIM Japan
- Quick setup: No physical SIM needed.
- Flexible plans: Pick according to your trip length and data needs.
- Hotspot support: Share your connection with other devices.
- Cost-effective: Avoid expensive roaming fees.
- Reliable in cities: Works well with major Japanese networks.
Cons of Ubigi eSIM Japan
- Data-only: No voice/SMS — calls to your family and friends will require using apps like WhatsApp.
- Variable performance in tough locations: Indoors or rural areas may see slower speeds.
- Possible throttling: “Unlimited” plans may reduce speed after a fair usage limit.
- Customer support: Some users report slow response times (however we received quick responses).
- Device quirks: Certain Android models may need manual adjustments.
Ubigi eSIM in Japan – Compared to other Local eSIM providers
| Feature | Ubigi eSIM Japan | Other eSIM providers | Local SIM |
|---|---|---|---|
| Network | Docomo and KDDI | KDDI / Softbank / Docomo | AU (KDDI) / Docomo / SoftBank |
| Coverage | Great in cities (5G on the two best networks) | Good in cities | Best nationwide |
| Speed | Fast | Fast | Fast |
| Voice / SMS | ❌ Data-only | ❌ Data-only | ✅ Local number |
| Hotspot | ✅ (no restrictions) | ✅ | ✅ |
| Ease of Setup | Very easy | Ranging from easy to requiring a QR code to verify | Needs purchase & ID |
| Best for | Heavy users | Being well rounded although can be more expensive | Having a local phone number |
Ubigi eSIM Japan Recommendations by Trip Length
- 1–5 days: The 3GB or 10GB Ubigi plan is usually enough for general data use.
- 6–14 days: The 10GB plan should have you covered for a week if you are a low data user. However, you may want to consider 25GB if you consume a lot of video and social media.
- 2–4 weeks: Ubigi 25GB plans could work out for a 2-week trip if you are careful with data, but you would want to have the 50GB plan especially when you are getting close to a 4-week trip.
- Still unsure which plan is best for you or how much data you need? In this case try the unlimited Ubigi plan which will allow you to stay online throughout your stay in Japan.
* Note: To give an idea of what medium to heavy data usage looks like even when using Wifi at hotels and friends and family homes, I used up over 50 GB of data during my recent 17-day trip to Japan.
Tips for Getting the Most Out of Ubigi eSIM in Japan
- Install your eSIM before flying.
- Enable data roaming once you land.
- Restart the phone or toggle airplane mode if needed.
- Use Wi-Fi indoors for heavy uploads or streaming although keep in mind that WiFi can be unsecure in public locations.
- Monitor usage to avoid any throttling on unlimited plans.
- Manually select the network if your phone picks the wrong one automatically.
Final Thoughts on Ubigi eSIM in Japan
Ubigi eSIM Japan plans offer convenience and reliability for travelers visiting Japan in 2025. From our own experience, we found that we could enjoy fast speeds suitable for checking directions on Google Maps, train times, staying connected with friends on Messenger, WhatsApp or Line, and streaming YouTube videos especially when planning out last minute research on the way to sightseeing spots.
Online you may find some outdated information about rural areas or underground spots seeing slower performance, however we did not find this was the case with Ubigi in underground locations in Tokyo, Osaka or Nagoya. When it came to rural areas, we were also well covered for internet browsing on Miyajima Island and Fukushima, although loading for Youtube videos did take several seconds when testing on the summit of Mount Misen.
When it comes to cost, when comparing to other eSIM providers like Airalo, Ubigi is often cheaper and provides longer validity periods. However, a key strength of Airalo is its range of plans such as 6 options for Unlimited plans vs 3 options on Ubigi. Overall, we found that Ubigi eSIM is a strong eSIM contender for your next Japan trip, especially as in some cases it has quicker loading time than other major competitors.
Finally if you are looking for a Ubigi eSIM Japan discount, feel free to use the code BESTJA10 when making your first purchase as this will give a 10% discount off the plan price.
We hope that you found this guide to Ubigi eSIM helpful for your travel planning. For additional Japan trip tips, be sure to check our travel section. Those fascinated by Japanese culture can dive into our culture section, and for a visual journey through Japan’s food, festivals, and attractions, follow our Instagram account.
All information is accurate as of the date of publishing the article, but we would recommend checking the Ubigi website for the latest information.
For disclosure, this is sponsored content, however we tried and tested the Ubigi eSIM Japan plan ourselves and provided our honest opinions about Ubigi eSIMs, from our experience using it in Japan. When you make a purchase through some links on our site, we may earn an affiliate commission, at no cost to you.
