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Japan eSIM: data plans compared by size, length and price
Seventeen Japan data plans from eSIMania's November 5, 2026 list, sorted by trip length, with the 15-day unlimited plan that costs more than 50 GB for a month and what the KDDI tag on eight plans means.
eSIMania listed 17 Japan plans on November 5, 2026, from 1 GB for a week at $2.40 to 50 GB for six months at $67.92. Five of them are unlimited-data plans of 3 to 15 days. Our eSIM guide covers how an eSIM works.
All 17 Japan plans
Prices are in US dollars, cheapest first, and each size links to that plan. A small note marks the plans tagged KDDI.
| Plan | Valid for | Price |
|---|---|---|
| 1 GB | 7 days | $2.40 |
| 2 GB | 15 days | $3.90 |
| 3 GB | 15 days | $6.00 |
| 3 GB | 30 days | $7.65 |
| 5 GB | 30 days | $9.00 |
| Unlimited dataKDDI label in the product code | 3 days | $14.43 |
| 12 GBKDDI label in the product code | 4 days | $14.46 |
| 10 GB | 30 days | $15.00 |
| 21 GBKDDI label in the product code | 7 days | $24.03 |
| Unlimited dataKDDI label in the product code | 5 days | $24.21 |
| 20 GB | 30 days | $25.50 |
| 30 GBKDDI label in the product code | 10 days | $35.43 |
| Unlimited dataKDDI label in the product code | 7 days | $37.20 |
| Unlimited dataKDDI label in the product code | 10 days | $44.80 |
| 50 GB | 30 days | $46.71 |
| Unlimited dataKDDI label in the product code | 15 days | $58.27 |
| 50 GB | 180 days | $67.92 |
eSIMania's own Japan page showed the same 17 prices on November 7. It struck out an older price on three plans: 50 GB for 30 days was $51.90, the 15-day unlimited plan was $68.55 and 50 GB for 180 days was $84.90.
eSIMania's Japan page lists the unlimited plans at 1,022,976 MB and states no speed or fair-use rule for them. Eight plans, the 12, 21 and 30 GB sizes plus all five unlimited ones, carry KDDI in their product code. KDDI runs the au, UQ mobile and povo phone brands. eSIMania says nothing more than the tag.
Which plan for which trip
For one week, 1 GB at $2.40 is enough if hotel Wi-Fi does most of the work. For streaming or a laptop on the hotspot, the KDDI-tagged 21 GB plan is $24.03 for 7 days, about $1.14 a gigabyte and $13.17 less than seven days of unlimited data.
Ten days to two weeks calls for 2 GB over 15 days at $3.90, the budget pick. Skip the 3 GB plan for 30 days at $7.65. It works out to $2.55 a gigabyte, more than the 1 GB week, and for $1.35 more the 5 GB plan gives you the same 30 days at $1.80 a gigabyte. Heavy users can take 30 GB for 10 days at $35.43, against $44.80 for ten unlimited days.
A month of ordinary use means 10 GB at $15.00 or 20 GB at $25.50. The 50 GB plan for 30 days, $46.71, is about 93 cents a gigabyte, the cheapest of the capped plans. Past a month, the 180-day 50 GB plan is $67.92, which is $21.21 more than the 30-day one.
The unlimited plans cost between $3.88 and $5.31 a day, and the 7-day plan is the dearest per day. The 15-day one, now $58.27, costs $11.56 more than 50 GB for a full month.
Your phone plan is the other price
On November 7, 2026, Verizon's TravelPass countries page listed Japan at $12 a day, so a week costs $84, against $24.03 for the 21 GB eSIM. T-Mobile's list of included destinations has Japan on it too: Experience Beyond and Go5G Next plans get up to 15 GB of high-speed data abroad, Experience More plans up to 5 GB, then speeds fall to 256 Kbps. On either of those T-Mobile tiers, a light user may not need an eSIM at all.
Which network you may land on
Japan has four main operators, and Opensignal's April 2026 report scored them on measurements from January 1 to March 31, 2026. On a 10-point scale for coverage of populated areas, NTT docomo scored 9.0, au 8.3, Rakuten Mobile 7.4 and SoftBank 7.3. au also won the reliability award, with 967 points out of 1,000.
eSIMania doesn't say that the KDDI tag on eight plans means au's network. If it does, those plans sit on the second-widest footprint in the report and its most reliable network. Opensignal's figures cover each operator's main brand only, not its sub-brands.
Measure your own use first
An iPhone counts your data use for you. Settings, then Cellular, lists which apps used data in the current period, and Reset Statistics starts a fresh count. Reset it a week before you fly, live normally, and read the total.
The same Apple page warns that Connectivity Assist uses cellular data when Wi-Fi is weak, busy or offline. In a hotel with poor Wi-Fi, that can drain the plan without any action on your part.
Wi-Fi you can count on, and where you can't
Japan's tourism board, on japan.travel, says the major international airports have free Wi-Fi in their terminals: Narita, Haneda and Kansai, plus New Chitose, Centrair and Fukuoka. Apple says an iPhone needs Wi-Fi or a hotspot to set up an eSIM, with exceptions for some eSIM-only models, so if it didn't install at home, finish it in the arrivals hall and give it the 10 minutes eSIMania's install guide allows for activation.
Japan's tourism board also warns that traditional ryokan and small minshuku inns may not offer Wi-Fi, especially in the mountains and countryside. A night or two in one is a reason to buy a size up. The board also points visitors to pocket Wi-Fi routers, rented from airport kiosks or delivered to the hotel. Every eSIMania plan allows a hotspot, though, so two travelers can share one phone's plan and skip the rental counter on the way home.
Japan and South Korea on one trip? On November 7, 2026, eSIMania's site listed a joint plan, 3 GB for 30 days at $12.96, and South Korea's own 3 GB plan at $7.65, the same as Japan's. The two single plans cost $15.30 but give you 3 GB in each country, so the joint plan is the dearer one per gigabyte, at $4.32 against $2.55.
Planning the trains? Our Japan rail passes guide compares the passes with single tickets and IC cards, and the Kyoto first-timer plan lays out three days in the city.
Frequently asked questions
Do I get a Japanese phone number with a Japan eSIM?
Not with these plans. eSIMania says they carry mobile data only, so there are no calls or text messages. WhatsApp and FaceTime calls run over the data.
Is the unlimited Japan plan really unlimited?
eSIMania's Japan page lists it at 1,022,976 MB and states no speed or fair-use rule. For a one-week trip, the 21 GB plan at $24.03 costs $13.17 less than seven unlimited days.
Can I install the eSIM after I land?
Yes, but the phone needs Wi-Fi to set it up. Japan's tourism board says Narita, Haneda and Kansai have free Wi-Fi in their terminals, and eSIMania's guide allows up to 10 minutes for activation.
Can two of us share one plan?
One eSIM sits on one phone, but eSIMania says every plan allows a Wi-Fi hotspot, so the second traveler can connect to the first phone, and every connected device draws on the same data.
Which network does a Japan eSIM use?
Eight of the 17 plans carry a KDDI tag in their product code, and KDDI is the company behind au. The other nine carry no tag, and eSIMania's Japan page names no network in its text.
