Travel guide
Japan eSIM, SIM or pocket Wi-Fi: how to stay online in Japan
You will lean on your phone in Japan far more than at home: maps through station mazes, train times, translation, restaurant bookings and disaster alerts. This guide compares the three ways to get data (eSIM, SIM card and pocket Wi-Fi), shows how much data a typical trip uses, explains why roaming from the US or Europe can get expensive, and walks you through setting up an eSIM before you fly. Our pick for an eSIM is Zwitchy, and we explain why.
In short
- An eSIM is the easiest option for most visitors: install it at home, switch it on when you land, no shop or pickup counter.
- Your phone must be unlocked and support eSIM. Check before you buy.
- Keep your home line on for calls and texts, but turn data roaming off on it so you are not charged roaming fees.
- Five to ten gigabytes covers most one-week trips; heavy video and hotspot users should go bigger.
- Save 110 (police), 119 (fire and ambulance) and the Japan Visitor Hotline 050-3816-2787 in your phone.
In this guide
Why you need data in Japan
Japan is easy to travel once you are online and surprisingly hard when you are not. Big stations like Shinjuku in Tokyo or Umeda in Osaka have dozens of exits, many signs outside the centre are in Japanese only, and plenty of small restaurants put their menu on a QR code. With data you can follow a map door to door, check live train times, translate a menu with your camera and get disaster alerts the moment they are issued.
Free Wi-Fi helps, but it does not replace mobile data. The major international airports offer free Wi-Fi in their terminals, and many hotels do too, but traditional ryokan and small family-run inns, especially in the mountains or the countryside, may not (JNTO (opens in a new tab)).
eSIM, SIM card or pocket Wi-Fi?
| Option | Best for | Watch out for |
|---|---|---|
| eSIM | Most travellers with a recent phone | Phone must be unlocked and support eSIM |
| Physical SIM card | Phones without eSIM | Swapping SIMs; buy at the airport or an electronics store |
| Pocket Wi-Fi | Groups sharing one connection, laptops | Another device to charge, carry and return |
| Roaming on your home plan | Very short trips | Daily charges add up fast |
An eSIM is a digital SIM you download by scanning a QR code. There is nothing to collect at the airport and nothing to return, and your own SIM stays in the phone, so your number still works for calls and texts. It is the simplest choice for most people with a phone from the last few years.
A physical SIM card works the same way but you swap it into your phone. You can buy one at the airport or at big electronics stores such as Bic Camera or Yodobashi Camera; JNTO gives a rough guide of about ¥3,000 for 1 GB over 30 days, and your phone must be unlocked (JNTO (opens in a new tab)).
A pocket Wi-Fi is a small router you carry and connect several devices to. Rental counters are at all major airports, or you can book online and have it sent to your hotel (JNTO (opens in a new tab)). It suits a family or group who stay together all day, less so friends who split up.
Roaming from the US, UK and Europe
If you live in the EU, note that "roam like at home" stops at the EU, the EEA, Moldova and Ukraine. Japan is not covered, and the EU warns that data roaming outside the EU and EEA can be expensive (Your Europe (opens in a new tab)). Some operators include Japan in their own offers, so check your plan. US and UK carriers usually sell daily international passes; Zwitchy's own comparison puts a typical carrier day pass at around $12, against $4.50 for its smallest Japan plan for the whole month (Zwitchy (opens in a new tab)). Over a two-week trip that difference adds up.
Our eSIM pick: Zwitchy
We recommend Zwitchy (zwitchy.io (opens in a new tab)) for Japan. Its Japan eSIM runs on SoftBank, one of the country's big networks, with 5G where available. It is data only, so you keep your own number, you can top up at any time, and you have 180 days from purchase to activate it. An eSIM you bought but never activated can be refunded in full within 30 days (Zwitchy (opens in a new tab)).
| Data (30 days) | Price (USD) |
|---|---|
| 1 GB | 4.50 |
| 3 GB | 10.50 |
| 5 GB | 16.50 |
| 10 GB | 30.50 |
| 20 GB | 59.00 |
| 30 GB | 86.50 |
| 50 GB | 142.50 |
Prices are as listed on Zwitchy's Japan page in October 2026 (Zwitchy (opens in a new tab)). There are also unlimited plans, which give you a daily high-speed allowance and then slower data, and a Pay As You Go option from $4.99 per gigabyte, with credit that never expires and works in other countries too. That one costs more per gigabyte, so it suits light users rather than heavy days.
How much data do you need?
It depends on how you use your phone, but these rough guides from travellers' typical use will get you close. Maps and train apps use little; video calls, uploading photos in full resolution and using your phone as a hotspot for a laptop use the most.
- Light (maps, messages, a little browsing): 3–5 GB a week
- Typical (plus social media and photo uploads): 5–10 GB a week
- Heavy (video calls, streaming, hotspot for a laptop): 20 GB or more
If you are not sure, start smaller and top up: topping up takes a minute in the app. Hotel Wi-Fi is the place for big downloads such as films for the flight home.
Set up your eSIM in five minutes
- Check your phone supports eSIM and is unlocked (Zwitchy device list (opens in a new tab)).
- Buy the plan a few days before you fly. The QR code arrives by email.
- Install it at home on Wi-Fi: open the QR code on a second screen and scan it from your phone's mobile settings (on iPhone: Settings, Cellular, Add eSIM). Nothing is used yet.
- Set the eSIM as your data line and keep your usual line for calls and texts.
- When you land, turn on data roaming for the eSIM line only. It connects to the local network and you are online (Zwitchy install guide (opens in a new tab)).
Do steps 1–4 at home on Wi-Fi, then the last one when you land.
Free Wi-Fi as a backup
Free hotspots are common in big cities: airports, stations, convenience stores and cafés. The Japan Wi-Fi auto-connect app, promoted by JNTO, lets you sign up once and then joins free hotspots from trusted providers for you, instead of registering for each network (JNTO (opens in a new tab)). Free Wi-Fi can be patchy and slow, so treat it as a backup and avoid online banking on open networks.
Apps worth installing before you go
- A maps app with public transport directions, plus offline maps of the cities you visit.
- A translation app that reads text through the camera, for menus and signs.
- LINE: Japan's everyday messaging app. Many restaurants, guesthouses and local friends use it rather than WhatsApp.
- Safety Tips: the Japan Tourism Agency's free app pushes alerts for earthquakes, tsunami, heavy rain, storms and volcanoes in 14 languages (Shinjuku City (opens in a new tab)).
- Your IC card: if your phone supports it, keep your Suica or PASMO in your wallet app.
Emergency numbers and keeping charged
Call 110 for the police and 119 for fire or an ambulance. For help in English at any hour, including after an accident, illness or natural disaster, call the Japan Visitor Hotline on 050-3816-2787, open 24 hours a day, 365 days a year (JNTO (opens in a new tab)). JNTO also advises keeping your phone and devices charged, because they can be indispensable in an emergency (JNTO (opens in a new tab)), so pack a small power bank.
Before you go
Sort out your data together with the rest of your arrival day: read our guides to entry rules for visitors and IC cards, and check the Tokyo weather for the days you land. If you head somewhere remote, such as the national parks of Hokkaido, download offline maps first, because signal can be thin far from towns.
Questions travellers ask
What is the best eSIM for Japan?
We recommend Zwitchy: it runs on SoftBank with 5G where available, plans start at $4.50 for 1 GB over 30 days, you keep your own number, and an unused eSIM can be refunded within 30 days.
Does my phone need to be unlocked for a Japan eSIM?
Yes. Your phone must be unlocked and support eSIM. Check your phone's settings or Zwitchy's device list before you buy.
Is there free Wi-Fi in Japan?
Yes, at major airports, many stations, convenience stores, cafés and most city hotels. The Japan Wi-Fi auto-connect app signs you in to free hotspots after one sign-up. Rural inns may not have Wi-Fi, so do not rely on it alone.
Does EU 'roam like at home' work in Japan?
No. It covers the EU, the EEA, Moldova and Ukraine. Some operators add Japan to their own offers, so check your plan before you travel.
Can I make phone calls with a data-only eSIM?
Not with a Japanese number. Use internet calls on LINE or WhatsApp, or your home line (your carrier may charge). Emergency numbers 110 and 119 still work.
Sources
We checked the facts on this page against these sources.
- Shinjuku City (for foreign residents and visitors)新宿区Safety Tips disaster alert app (opens in a new tab)
- Zwitchy eSIMJapan eSIM plans and prices (opens in a new tab)
- Zwitchy eSIMHow to install an eSIM, step by step (opens in a new tab)
- Zwitchy eSIMWhich phones support eSIM (opens in a new tab)
- Japan National Tourism Organization (JNTO)日本政府観光局Wi-Fi, SIM cards and pocket Wi-Fi in Japan (opens in a new tab)
- Japan National Tourism Organization (JNTO)日本政府観光局Japan Wi-Fi auto-connect app (opens in a new tab)
- Japan National Tourism Organization (JNTO)日本政府観光局Japan Visitor Hotline and key numbers (opens in a new tab)
- Japan National Tourism Organization (JNTO)日本政府観光局What to do in an emergency (opens in a new tab)
- Your Europe (European Union)EU roaming rules and countries outside the EU (opens in a new tab)
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