Ubigi Japan: review, network and comparison with PlanJapan (2026)
TL;DR
Ubigi is a French eSIM provider (subsidiary of Transatel/NTT) with a good app and varied plans for Japan. The service uses the NTT Docomo and KDDI networks, with decent speeds in cities. However, the cost per GB remains higher than specialized competitors, the "unlimited" plans apply a fair use policy (speed reduced after 25 to 60 GB depending on duration), and customer support can be slow. For a trip to Japan, PlanJapan offers a more specialized alternative, often cheaper and with responsive multilingual support.
Ubigi: who is this eSIM provider?
Ubigi is a French brand launched in 2017 by Transatel, a telecommunications company based in Paris. Since 2019, Transatel has been a 100% subsidiary of NTT (Nippon Telegraph and Telephone), the Japanese telecom giant — the parent company of NTT Docomo.
This affiliation with NTT is a strong selling point: Ubigi is technically connected to Japan's largest carrier. The company offers eSIMs for over 200 destinations, with a mobile app available in multiple languages. On Trustpilot, Ubigi has a score of 4.4/5 from about 6,800 reviews — a respectable score in the sector. If you're looking for a broader comparison, check our best eSIM Japan 2026 guide.
For Japan specifically, Ubigi connects to the NTT Docomo and KDDI networks, giving it access to extensive coverage across the archipelago. This is a real advantage over some competitors that only connect to SoftBank.
Ubigi plans for Japan in 2026
Ubigi offers a fairly wide range of Japan plans, split into three categories: fixed-volume plans, one-time unlimited plans, and monthly subscriptions. Here are the details:
Fixed-volume plans (one-time purchase)
| Plan | Duration | Price | Price/GB |
|---|---|---|---|
| 5 GB | 30 days | ~$8 | ~$1.60/GB |
| 10 GB | 30 days | ~$17 | ~$1.70/GB |
| 25 GB | 30 days | ~$33 | ~$1.32/GB |
"Unlimited" plans (one-time purchase)
| Plan | Duration | Price | Full-speed data | After fair use |
|---|---|---|---|---|
| Unlimited 7 days | 7 days | ~$25 | 25 GB | 2 Mbps |
| Unlimited 15 days | 15 days | ~$39 | 30 GB | 2 Mbps |
| Unlimited 30 days | 30 days | ~$66 | 60 GB | 2 Mbps |
Monthly subscriptions
| Plan | Price/month | Commitment |
|---|---|---|
| 5 GB/month | ~$8 | 3-month minimum |
| 20 GB/month | ~$20 | 3-month minimum |
| Unlimited/month (60 GB full speed) | ~$46 | 3-month minimum |
Important note: Ubigi prices are displayed in USD on their site. The exact amount charged depends on the exchange rate at the time of purchase.
Ubigi's advantages for Japan
Let's be objective: Ubigi has real strengths, especially for international travelers.
1. A French brand with a multilingual app
The Ubigi app is available in multiple languages, making plan management, usage tracking, and top-ups easier. The interface is clean and well-designed.
2. Strong networks in Japan
Ubigi connects to the NTT Docomo and KDDI networks in Japan. These are the country's two best carriers in terms of coverage. In cities (Tokyo, Osaka, Kyoto), speeds are generally excellent — users report speeds between 50 and 100 Mbps on 4G, and up to 300 Mbps on 5G.
3. A reusable eSIM
The Ubigi eSIM profile is reusable: you can buy a new Japan plan (or another country) without reinstalling the eSIM. Convenient if you travel frequently to different destinations.
4. Wide choice of plans
With options ranging from 5 GB to unlimited, including monthly subscriptions, Ubigi covers a wide spectrum of needs. Few providers offer this much flexibility.
Ubigi's limitations to know before buying
Despite its qualities, Ubigi has several weak points that regularly come up in user feedback.
1. Fair use on "unlimited" plans
This is the most important point to understand. Ubigi's "unlimited" plans are not truly unlimited at constant speed. After consuming the full-speed data volume (25 GB over 7 days, 30 GB over 15 days, 60 GB over 30 days), speed is reduced to 2 Mbps for the remainder of the period.
At 2 Mbps, you can still browse, send messages, and use Maps. But forget video streaming at decent quality, smooth video calls, or comfortable tethering. It's better than the 128 kbps throttling some competitors apply, but it's not truly unlimited.
2. Higher prices than specialized competitors
For a 30-day plan with an equivalent data volume, Ubigi is often more expensive than a Japan specialist like PlanJapan. The unlimited 30-day plan at ~$66 with Ubigi is well above the market average. And USD pricing means international buyers pay an exchange rate premium.
3. Documented issues on Google Pixel
Several users of Google Pixel 9 and Pixel 10 have reported connectivity issues with Ubigi in Japan. The app can encounter difficulties during setup, and 5G isn't always available on these devices due to network-specific settings. Ubigi offers dedicated Pixel support pages, but the issue persists for some users.
4. Sometimes slow customer support
This is the most frequent negative point in reviews. Ubigi offers no phone support — only a contact form and a chatbot. Several users report response times of 4 hours to 3 days to get human assistance. Some report sending more than 10 emails to resolve a simple issue. On weekends, support is virtually nonexistent.
When you're at Narita Airport at 10 PM and your eSIM won't connect, waiting 4 hours for a response is not an option.
5. Three-month commitment on subscriptions
Ubigi's monthly plans require a minimum 3-month commitment. If you're going to Japan for 2 weeks, the subscription makes no sense — you'll pay for 3 months for 15 days of use. One-time plans are more suited for travelers, but they're also more expensive per GB.
Ubigi vs PlanJapan comparison: the numbers
For a clear picture, here's a factual comparison between both providers on the criteria that matter for a Japan trip:
| Criterion | Ubigi | PlanJapan |
|---|---|---|
| Headquarters | France (Transatel/NTT) | France |
| Japan network | NTT Docomo + KDDI | NTT Docomo |
| 10 GB plan | ~$17 / 30 days | Available / 30 days |
| 20-25 GB plan | ~$33 (25 GB) / 30 days | Available (20 GB) / 30 days |
| 50 GB plan | Not available one-time | Available / 30 days |
| Unlimited 7 days | ~$25 (25 GB full speed, then 2 Mbps) | Available (no fair use) |
| Unlimited 30 days | ~$66 (60 GB full speed, then 2 Mbps) | Available (no fair use) |
| Hotspot | Yes | Yes, without restrictions |
| Fair use / throttling | Yes (2 Mbps after threshold) | No |
| Multilingual support | Yes (form + chatbot, no phone) | Yes (EN, FR, ES) |
| Support response time | 4 hrs to 3 days (user reports) | Responsive |
| Mobile app | Yes (iOS + Android) | No (QR code management) |
| Pixel 9/10 compatibility | Issues reported | Compatible |
| Billing currency | USD | EUR |
| Specialization | 200+ destinations | Japan only |
Key takeaway: Ubigi has the advantage of a mobile app and a reusable multi-destination eSIM. PlanJapan has the advantage of Japan specialization, competitive pricing, a dedicated 50 GB plan, unlimited without fair use, and more responsive support.
Which network does Ubigi use in Japan?
This is an often misunderstood point. Ubigi connects in Japan to two networks: NTT Docomo and KDDI (au). Your phone automatically switches to the strongest network based on your location.
NTT Docomo
The reference network in Japan, with 99.9% population coverage. Excellent in rural areas, on the Shinkansen, and on islands. This is the network PlanJapan uses exclusively.
KDDI (au)
Japan's second carrier, with very good speeds in cities. Coverage is slightly less extensive than Docomo in remote rural areas, but remains very good for standard tourist use.
In practice, this dual Docomo + KDDI coverage is a strong point for Ubigi. That said, for the vast majority of travelers, NTT Docomo coverage alone is more than sufficient — including in Okinawa, Tohoku, and on Mount Fuji.
Ubigi Japan: who is it the right choice for?
Ubigi isn't a bad service — it's a generalist service with strengths and weaknesses. Here's who it may suit:
Ubigi is a good choice if:
- You travel regularly to multiple countries and want a single reusable eSIM
- You absolutely want a mobile app to manage your plan
- You're going for a long stay (3+ months) and the monthly subscription makes sense
- You have low data usage (5-10 GB) and Ubigi's basic plans are sufficient
PlanJapan is a better choice if:
- You're going specifically to Japan and want the most tailored offer
- You want a 50 GB plan — Ubigi doesn't offer it as a one-time purchase
- You need a truly unlimited plan without throttling
- Responsive multilingual support is important to you
- You use a recent Google Pixel and want to avoid compatibility issues
Frequently asked questions
Does Ubigi work well in Japan?
Yes, Ubigi generally works well in Japan thanks to its connection to the NTT Docomo and KDDI networks. City speeds are good (50-100 Mbps on 4G). The main limitations are the fair use on unlimited plans (reduction to 2 Mbps after a certain volume) and reported issues on Google Pixel 9 and 10. For most travelers in urban areas, the service is reliable.
Is Ubigi cheaper than PlanJapan for Japan?
No, in most cases. Ubigi lists its prices in USD, which adds a conversion cost for non-US buyers. The 30-day unlimited plan at ~$66 is significantly more expensive than specialized alternatives. Additionally, Ubigi doesn't offer a 50 GB one-time plan — a very popular format for travelers on 2-week trips. PlanJapan offers competitive pricing without hidden fees.
Is Ubigi's unlimited plan truly unlimited?
Partially. Ubigi applies a fair use policy on all unlimited plans: after 25 GB (7 days), 30 GB (15 days), or 60 GB (30 days) at full speed, the speed is reduced to 2 Mbps. That's enough for Maps and messaging, but not for streaming or video calls. With PlanJapan, the unlimited plan doesn't apply any fair use.
Does Ubigi work on Google Pixel in Japan?
Ubigi is officially compatible with Google Pixel, but connectivity issues have been reported on Pixel 9 and Pixel 10 in Japan. The app can encounter bugs during installation, and 5G access isn't guaranteed on these devices. If you have a recent Pixel, check Ubigi's support pages before buying, or choose a provider without documented issues on these models.
Which network does Ubigi use in Japan?
Ubigi connects to the NTT Docomo and KDDI networks in Japan. Your phone automatically switches between the two based on signal strength. These are Japan's two best carriers in terms of coverage. PlanJapan uses exclusively NTT Docomo, the network with the most extensive coverage (99.9% of the population).
How to contact Ubigi support?
Ubigi offers an online contact form and a chatbot on its website. There is no phone support. Response times vary: some users report 4 hours, others up to 3 days. On weekends, support is limited. If you need quick assistance during your trip, this is a point to consider.
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Our recommendation
Ubigi is a serious provider with a good app and the advantage of being reusable in 200+ countries. If you're a frequent multi-destination traveler, it's worth considering.
However, for a trip specifically to Japan, PlanJapan offers better value: competitively priced plans designed for 1-4 week stays (including the 50 GB option, absent from Ubigi's one-time offerings), unlimited without fair use, and responsive multilingual support. The NTT Docomo network covers 99.9% of the Japanese territory — Shinkansen, rural areas, and islands included.
If you're torn between the two, ask yourself this: will I reuse this eSIM in other countries soon? If yes, Ubigi makes sense. If your priority is the best connection in Japan at the best price, PlanJapan is the most suitable choice.