Today I Learned
Airalo vs Ubigi for Japan (2026): Which eSIM Should You Buy?
Airalo vs Ubigi for Japan, on published Aug 2026 plans: Airalo sells unlimited day plans (3GB/day full speed), Ubigi cheaper fixed-GB data on NTT Docomo + KDDI 5G. Here's which to buy.
Short answer
If you know roughly how much data you need, buy Ubigi. Its Japan plans run on KDDI and NTT Docomo with 5G and tethering allowed, and the prices are hard to argue with: 10GB for 7 days at US$14, or 25GB for 30 days at US$32. If you want to never think about data at all, buy Airalo — its Japan storefront now sells unlimited plans (¥4,450 for 7 days as displayed in August 2026), with the caveat that “unlimited” means 3GB per day at full speed before a 1 Mbps throttle kicks in until the daily reset.
Neither gives you a Japanese phone number. If you need one — for Tabelog reservation SMS, ride-hailing apps, anything that verifies by Japanese number — neither of these is your answer, and we’ll point you to the right one below.
The rest of this article is the published-plan evidence, checked against Airalo’s and Ubigi’s official pages on August 19, 2026.
How this comparison works
This is a specification and price comparison based on the plans published on airalo.com and cellulardata.ubigi.com as of August 19, 2026 — every figure below comes from an official plan page or policy page, all linked in the sources. It is not a speed test. Two notes on currency: Airalo’s storefront localizes prices and displayed yen to us; Ubigi’s plan pages price in US dollars (Ubigi’s pages note billing is also available in EUR, GBP, JPY, CNY, AUD, and CAD). Prices in both stores can change and may display differently in your region.
Airalo’s Japan lineup (as displayed, August 2026)
Airalo is the world’s biggest eSIM marketplace, and its Japan offer has consolidated around unlimited day-based plans. When we checked the Japan page in August 2026, the storefront displayed unlimited plans only — if you see fixed-GB options in the Airalo app, treat the in-app price as authoritative.
| Validity | Data | Price (as displayed) |
|---|---|---|
| 3 days | Unlimited | ¥1,900 |
| 5 days | Unlimited | ¥2,800 |
| 7 days | Unlimited | ¥4,450 |
| 10 days | Unlimited | ¥5,700 |
| 15 days | Unlimited | ¥7,900 |
| 30 days | Unlimited | ¥11,350 |
The fine print that matters is Airalo’s Fair Use Policy for unlimited plans: the default high-speed allowance is 3GB per day, after which speeds drop to 1 Mbps for the rest of that day, resetting every 24 hours counted from activation. (Airalo notes a different threshold, where one applies, is shown in the package details before purchase.) 1 Mbps still handles maps and messaging; it does not handle video calls or uploads comfortably.
Network: the storefront lists SoftBank plus one additional network it doesn’t name on the page. Tethering policy for the Japan plans isn’t stated on the page we checked — confirm in the app before relying on hotspot use.
Ubigi’s Japan lineup
Ubigi is the consumer eSIM brand of Transatel, and its Japan plan pages are unusually specific about what you’re buying. All plans are data-only, run on KDDI and NTT Docomo with 5G indicated, and explicitly state “data sharing allowed” — tethering is officially fine. Plans auto-activate when you land in Japan (“Smartstart”), and you can top up in the app even without Wi-Fi or remaining data.
| Plan | Validity | Price | Type |
|---|---|---|---|
| 10GB | 7 days | US$14 | One-off |
| 5GB | 15 days | US$10 | One-off |
| 25GB | 30 days | US$32 | One-off |
| Unlimited (60GB full speed, then 2 Mbps) | Monthly | US$45/month | Auto-renewing subscription |
Two things to note. First, the value on the one-off plans is the headline here: US$14 for 10GB over a week undercuts most of the Japan eSIM market. Second, the unlimited plan is a monthly subscription that renews automatically and can only be cancelled after three months — it’s built for long-stayers and frequent visitors, not a two-week holiday. Tourists should stick to the one-off plans.
Head-to-head
| Airalo | Ubigi | |
|---|---|---|
| Plan model | Unlimited day plans (as displayed Aug 2026) | Fixed-GB one-off plans + monthly unlimited |
| Networks in Japan | SoftBank + 1 unnamed network | KDDI + NTT Docomo |
| 5G | Not stated on the plan page we checked | Yes (indicated on plan pages) |
| Full-speed limit | 3GB/day, then 1 Mbps until daily reset (FUP) | Fixed plans: full speed until the bucket is used. Unlimited: 60GB, then 2 Mbps |
| Tethering | Not stated on the Japan page we checked | Allowed (“data sharing allowed”) |
| Activation | Install by QR before you fly | Auto-activates on arrival in Japan |
| Japanese phone number | No | No |
| 7-day cost | ¥4,450 (unlimited) | US$14 (10GB) |
| 30-day cost | ¥11,350 (unlimited) | US$32 (25GB) |
Which one should you buy?
| Your trip | Buy | Why |
|---|---|---|
| 5–7 days, maps + translation + social | Ubigi 10GB / 7 days (US$14) | 10GB comfortably covers a week of normal tourist use, on Docomo + KDDI. |
| 7 days, video calls and heavy uploads every day | Airalo Unlimited 7 days (¥4,450) | If you genuinely exceed 3GB some days, no bucket to drain — just remember the 1 Mbps throttle past 3GB/day. |
| 2 weeks, light use | Ubigi 5GB / 15 days (US$10) | The cheapest confirmed way to stay connected for a fortnight. |
| 3–4 weeks | Ubigi 25GB / 30 days (US$32) | Less than a third of Airalo’s 30-day unlimited price, and 25GB is a lot of maps. |
| Rural Japan — Tohoku, Hokkaido, mountain onsen | Ubigi | NTT Docomo is the network with the strongest rural reputation in Japan, and Ubigi runs on it. |
| Multi-month stay or frequent return trips | Ubigi Unlimited (US$45/month) | 60GB full speed monthly; just know it auto-renews with cancellation after three months. |
| You want one wallet/app for every country you visit | Airalo | The marketplace model is Airalo’s real product; Japan is one storefront among 200+. |
Here’s the honest arithmetic that decides most cases: Airalo’s unlimited plan gives you full speed up to 3GB per day — a ceiling of about 21GB of high-speed data across a 7-day trip, if you max out every single day. Most travelers don’t come close, which means most travelers are paying an unlimited premium for usage a US$14 10GB Ubigi plan would have covered at full speed anyway. Buy Airalo’s unlimited when the predictability is worth it to you; buy Ubigi when the math is.
Ready to buy? Get the Airalo Japan eSIM here, or go straight to Ubigi’s official plan pages: 10GB / 7 days, 5GB / 15 days, 25GB / 30 days. The Airalo link is an affiliate link; the Ubigi links are not. The recommendation logic above doesn’t change either way.
What neither of them gives you: a Japanese phone number
Airalo and Ubigi are both data-only. That’s fine for maps, translation, and calling home over LINE or WhatsApp — but Japan still routes a surprising amount of daily life through Japanese SMS: Tabelog and OpenTable reservation confirmations, sign-up verification for the GO and DiDi ride-hailing apps, konbini package pickup codes. If your trip includes any of that, the product you want is a voice+data SIM with a real 070/080/090 number, and the main player there is Mobal — we compare it against Airalo and Sakura Mobile in Mobal vs Airalo vs Sakura: one feature decides the Japan SIM.
The same framing answers the “Ubigi vs Sakura Mobile” question we see in search: Ubigi is the cheap, self-serve, fixed-GB eSIM; Sakura Mobile is the Tokyo-based, support-desk-and-unlimited provider at a higher price. They’re solving different problems, and the three-way article above covers where Sakura fits.
For the full field — Klook, Mobal, Sakura, and friends — start at our hub: the best eSIM for Japan in 2026. And once you’ve bought one, here’s the step-by-step airport activation guide so you’re online before you clear customs.
Closing
Airalo vs Ubigi isn’t really a brand fight — it’s a plan-model fight. As of August 2026, Airalo sells Japan as unlimited-by-the-day (with a 3GB/day full-speed allowance under its Fair Use Policy), and Ubigi sells Japan as cheap fixed buckets on KDDI + Docomo 5G. Apparently the only question you need to answer is whether you’d rather pay for a ceiling you’ll probably never hit, or a bucket you can actually measure. For most trips, the bucket wins.