Japan runs on your phone: train transfers, walking directions through stations with a dozen exits, and pointing your camera at a menu to translate it. Here's what a Japan eSIM actually costs, which one fits your trip, and how to set it up before you fly.
Saily for most trips; any of the three for unlimited
For a typical one- or two-week trip, a fixed-data plan is the better buy: Saily's 5 GB and 10 GB plans cost $10.99 and $17.99 and stay valid for 30 days, run on KDDI and SoftBank, and switch on automatically when you land. If you want unlimited data, the three providers were within about $1–5 of each other, with Airalo marginally cheapest.
See Saily's Japan plans →Fixed-data plan prices
Holafly only sells unlimited plans for Japan, so this is Saily against Airalo. Validity matters as much as price: a plan that expires after 7 days is only cheap if your trip is 7 days.
| Data | Saily | Airalo |
|---|---|---|
| 1 GB | $3.997 days | $4.003 days |
| 3 GB | $7.9930 days | $7.503 days$8.007 days |
| 5 GB | $10.9930 days | $10.007 days$10.5015 days$11.0030 days |
| 10 GB | $17.9930 days | $17.007 days$17.5015 days$18.0030 days |
| 20 GB | $24.9930 days | $24.0015 days$25.0030 days |
Prices in USD from saily.com and airalo.com, checked 29 September 2026.
What that means: at 30-day validity the two are effectively the same price. Airalo is 50 cents to $1 cheaper if you're sure your trip fits a shorter 7- or 15-day window. Saily's plans are simpler — almost everything lasts 30 days, so a delayed flight or an extra few days won't cost you.
Unlimited plan prices
| Days | Saily | Airalo | Holafly |
|---|---|---|---|
| 3 | $11.99 | $11.50 | $11.90 |
| 5 | $18.99 | $17.00 | $20.50 |
| 7 | $26.99 | $26.50 | $27.50 |
| 10 | $34.99 | $34.50 | $36.50 |
| 15 | $48.99 | $48.00 | $50.50 |
| 30 | $71.99 | $69.00 | $73.90 |
Prices in USD from each provider's Japan page, checked 29 September 2026. Saily also sells every length from 1 to 30 days.
"Unlimited" rarely means unlimited full speed. Saily states 5 GB per day at full speed, then up to 1 Mbps. Holafly states a fair-usage policy that can slow speeds for up to a day, and lets you share 1 GB per day as a hotspot. Airalo's Japan page didn't list its unlimited limits, so check the plan details before buying.
Unlimited is worth it if you'll stream video or tether a laptop on mobile data. For maps, messaging and social media, a 10 GB plan covers most two-week trips for far less.
Which one to pick
- Most travelers (1–3 weeks, normal use): Saily 5 GB or 10 GB. Same price as Airalo's 30-day plans, activates on arrival, and you can add another plan in the app if you run low.
- Short trip, fixed dates, lowest price: Airalo's 7- or 15-day plans shave off up to $1.
- Heavy users who want unlimited: Airalo was cheapest on every length; Saily's clearly stated 5 GB/day full-speed allowance is the easiest to plan around; Holafly suits you if you want to share data by hotspot.
- Japan as one stop on a longer Asia trip: a regional plan can beat several single-country plans. Saily's Asia and Oceania plan covers 22 countries including Japan, and Airalo sells an Asia plan too — compare it against buying each country separately.
Networks and coverage
Japan has several nationwide networks, including NTT Docomo, KDDI (au) and SoftBank. Travel eSIMs connect as roaming users on one or more of them:
- Saily: partners with KDDI and SoftBank; 4G/LTE and 5G where available.
- Airalo: SoftBank, plus one other network listed on its site.
- Holafly: KDDI and SoftBank; 4G/LTE and 5G where available.
Access to more than one network helps in rural areas and mountain towns, where one network may be stronger than the other. None of the three includes a Japanese phone number — they're data-only.
How much data you need in Japan
Using the rates from the trip data calculator — three hours a day of maps, messaging and browsing, an hour of social media and an hour of music, with 40% of your time on hotel WiFi:
- 7 days: about 3.6 GB → a 5 GB plan
- 14 days: about 7.2 GB → a 10 GB plan
- 21 days: about 10.9 GB → a 20 GB plan, or 10 GB plus a top-up
Camera translation and constant map use in big stations add up, so round up rather than down. Put in your own habits with the calculator.
Setting up before you fly
- Check your phone is eSIM-compatible and carrier-unlocked. A phone locked to your home carrier won't accept another provider's eSIM.
- Install the eSIM at home over WiFi. Installation needs a connection; activation can wait. Saily plans can be activated any time within 180 days of purchase and switch on automatically when you arrive.
- On landing, set the eSIM as your data line and turn on data roaming for it. Roaming must be on for the eSIM line — that's normal for travel eSIMs and doesn't cost extra.
- Turn off data roaming on your home SIM so it can still receive calls and texts without running up charges.
eSIM vs pocket WiFi vs airport SIM
- eSIM: set up before you leave, nothing to collect or return, and priced from a few dollars. The catch is it needs a compatible, unlocked phone.
- Pocket WiFi rental: one device can serve a whole group, but you have to pick it up, keep it charged, carry it everywhere and return it.
- Physical tourist SIM: works in unlocked phones without eSIM support, but means a queue on arrival and a tiny card to swap.
Using a VPN in Japan
VPNs are legal in Japan. You'll likely lean on free WiFi in hotels, stations and cafés to save data — shared networks are exactly where a VPN earns its keep. See the best VPN for airport and hotel WiFi, and if you want your home streaming library while you're away, the streaming guide.
More country guides: Thailand · USA · Turkey.
Frequently asked questions
Do I need an eSIM for Japan?
You don't strictly need one, but mobile data makes Japan much easier: train connections, Google Maps walking directions and camera translation of menus and signs all need a connection. An eSIM is usually cheaper than roaming and quicker than buying a SIM or renting pocket WiFi at the airport.
What is the cheapest eSIM for Japan?
On 29 September 2026, the cheapest fixed-data plans were within a few cents of each other: Saily charged $10.99 for 5 GB valid 30 days and Airalo $11.00 for the same. Airalo was slightly cheaper for short-validity and unlimited plans, for example $26.50 for 7 days unlimited versus $26.99 at Saily and $27.50 at Holafly.
Which network do Japan travel eSIMs use?
Saily says it partners with KDDI and SoftBank, Holafly lists KDDI and SoftBank, and Airalo lists SoftBank plus one other network. KDDI (au) and SoftBank are two of Japan's major nationwide networks.
Do Japan eSIMs include a phone number?
No. These are data-only eSIMs, so use WhatsApp, FaceTime or other internet calling. Keep your home SIM active if you need to receive texts such as bank codes, but turn off its data roaming to avoid charges.
Is it legal to use a VPN in Japan?
Yes. VPNs are legal in Japan, and using one on hotel, station or café WiFi is a sensible precaution.