Pocket wifi or eSIM in Japan: Suica and data

Japan is the country where having data from the moment you land makes the biggest difference: the Tokyo metro is a maze you navigate with your phone, the menus are in Japanese, half of everything is paid by app, and even the capsule hotel locker has a QR code on it. It is also a country where roaming on your home tariff gets expensive fast. This guide covers the options, which one suits your trip, and how to arrive with everything ready.

Ways to get online in Japan

Roaming on your home plan

Japan sits outside every European roaming agreement and outside most “included destinations” lists worldwide. What carriers usually offer is a daily bundle with a few hundred megabytes for a sum that stings over a two-week trip, or straight per-megabyte billing, which is how people come home to a three-figure bill for a week of maps. Check your own tariff before you go: some carriers do have a reasonable weekly add-on, but it is the exception.

A physical SIM at the airport

Narita, Haneda and Kansai all have counters and vending machines with tourist SIMs valid for 7, 15 or 30 days. They work fine. The downsides: you do it with your passport in hand after a fourteen-hour flight, you have to pop out your home SIM and not lose it, and it costs more than buying ahead. Tourists cannot sign contract lines in Japan, so everything is prepaid.

Pocket wifi

A wallet-sized router you rent and hand back at the airport. It made sense when few phones took an eSIM: it gives several devices internet at once. Today it only wins if you are travelling as a group with older handsets. It is one more thing to charge, one more thing to return, and per person it costs more than an eSIM.

An eSIM

You buy before you fly, a QR code arrives by email, you install it at home on wifi, and when you land your phone connects itself to a Japanese network. Your usual SIM stays in the phone for calls if you need it, with its data switched off. It is the easiest option if your phone takes one — how to check is below.

Real coverage: who runs the networks and where it thins out

Japan has three big operators — NTT Docomo, KDDI (au) and SoftBank — plus the newer Rakuten Mobile. Docomo has the reputation for reaching furthest into rural areas; SoftBank and KDDI are very close to each other in the cities. Travel eSIMs ride on one of them, sometimes two: the plan page tells you which.

Coverage is excellent everywhere the vast majority of visitors go: Tokyo, Kyoto, Osaka, Hiroshima, Nara, Hakone, Fukuoka. There is signal on the metro, on the shinkansen (with brief drops in mountain tunnels) and on most local lines. Where it gets patchy:

• Hiking and mountain routes — the Japan Alps, the Kumano Kodo, the climb up Fuji: expect stretches with nothing. Download the map first.
• Small islands around Okinawa or in the Inland Sea: fine in the villages, unreliable in the coves.
• Rural Hokkaido and Tohoku: fine on the main roads, uneven in the valleys.

And the warning that applies to us and to everyone else: an eSIM hooks onto a local operator’s network, it does not bring its own. Where there is no mast, no eSIM on earth will help — not ours, not anyone’s. If your route touches the list above, download the maps and tell someone where you are going.

Japan’s 3G networks have been switching off since 2024, so your phone needs 4G LTE — anything from the last eight years has it. There is 5G in the cities, but 4G is more than enough for what you do on a trip.

How much data you need in Japan

Japan burns through data faster than other destinations for three reasons: Google Maps in transit mode is open all day, you translate menus and signs with the camera constantly, and the place is so photogenic that everything gets uploaded.

Kind of trip	Typical use	Plan that fits
Cities, maps, messages, the odd photo	300-500 MB a day	3-5 GB for a week
The above plus daily social media and stories	700 MB - 1 GB a day	10 GB for ten days, or unlimited
Video, video calls, tethering a laptop	Over 1.5 GB a day	Unlimited by the day

If you are unsure, go unlimited: in Japan the gap between a 10 GB plan and a weekly unlimited one tends to be small, and losing your map in Shinjuku at eleven at night is nobody’s idea of fun. The Spanish guide ¿Cuántos GB necesito para viajar? has the per-app numbers.

Installing and activating the eSIM before you fly

1. Check compatibility: dial *#06# and look for the EID. If it is there, the phone takes an eSIM — and it has to be carrier-unlocked. iPhones from the XR/XS, Pixels from the 3 and Galaxy S from the S20 all qualify; the full list is on the compatibility page.
2. Buy a plan covering your dates. Validity starts with the first connection in Japan, not at purchase, so you can buy weeks ahead.
3. Install the QR at home on wifi: iPhone → Settings → Mobile Data → Add eSIM; Android → Settings → Connections → SIM manager → Add eSIM. Name it “Japan”.
4. Set up the lines: home SIM as default for calls and texts, eSIM as the mobile data line, data roaming on for the eSIM and off for your home line. That last part is what prevents the surprise bill.
5. On landing: turn off airplane mode, wait a few seconds for “docomo”, “au” or “SoftBank” to appear, and open the map. If nothing happens, toggle airplane mode; if it still will not connect, go back to step 4.

Every menu, step by step, is in What is an eSIM and how does it work?.

Apps worth installing before you go

• Google Maps: transit mode in Japan is gold — it gives you the platform, the carriage and the fare. Download Tokyo, Kyoto and Osaka for offline use anyway.
• Japan Travel by Navitime: train and metro routing built for visitors, including the JR Pass and regional passes.
• Google Translate with the Japanese pack downloaded: the camera reads menus and signs instantly, no data needed.
• Suica or PASMO in your phone wallet: tap for the metro, buses, vending machines and convenience stores. Topping it up from the phone is what needs data.
• Tabelog for restaurants: Japanese ratings are more reliable than Google’s, and harsher — 3.5 is already very good.
• Klook or the official JR site for passes and reserved trains; Uber works in Tokyo, though hailing a taxi is just as easy and sometimes cheaper.

Connectivity tips that save you grief

• Public wifi wants you to register and often refuses to connect. With an eSIM you skip the whole ritual.
• Convenience stores are your base: 7-Eleven, Lawson and FamilyMart have ATMs that take foreign cards, wifi, and decent food at any hour.
• Cash still matters: card acceptance has improved enormously, but small restaurants, temples and markets want yen. Withdraw at a convenience store ATM.
• Calls: the eSIM is data only. To ring a Japanese hotel, use your home line for one short call, or ask your accommodation to call for you.
• Ryokan and rural stays: email your arrival time before you leave the city, in case you lose signal on the way.
• Battery: maps, translation and photos drain it. A small power bank saves the afternoon.

What it costs

The price block at the top of this guide shows what a Japan eSIM costs in the MovaSim catalogue right now — the unlimited-by-day option and the cheapest per-GB one — and the Japan page lists every plan with the countries it covers. The QR arrives by email in seconds. The installation steps and the advice above work just as well with any provider.