SIM, eSIM and pocket WiFi in Japan: how to stay connected

Having data in Japan is not optional — maps, train schedules, real-time translation, and navigation are too useful to rely on hotel WiFi alone. The three main options are a tourist data SIM, an eSIM, and a pocket WiFi router. Each has advantages and drawbacks depending on how you travel.

Tourist SIM (physical card)

A Japan data SIM can be bought at Narita and Haneda airports immediately on arrival, at electronics stores like Yodobashi and Bic Camera, and at airport convenience stores. You can also order one online in advance and collect it at the airport or have it delivered to your home country.

The most common operators for tourists are IIJmio, OCN Mobile, b-mobile, and the own-brand SIMs from Yodobashi and Amazon Japan. Typical plans are 3, 7, 15, or 30 days with unlimited data (with speed reduction above a daily threshold).

Advantages:

• Affordable (from ¥2,000–4,000 for 7–15 days)
• No extra battery or additional device needed
• Easy to buy on arrival

Drawbacks:

• Data only — tourist SIMs in Japan generally don’t include calls or SMS
• Requires an unlocked phone compatible with Japanese LTE bands (Band 1/3/19 for NTT Docomo, the most widespread network)
• If travelling as a couple or group, each person needs their own SIM

eSIM

The eSIM is the most convenient option if your phone supports it (most smartphones from 2019–2020 onwards do). You buy it online before travelling and activate it by scanning a QR code — there is nothing physical to collect.

Popular eSIM providers for Japan: Airalo, Holafly, Ubigi, IIJmio (which also offers eSIM), and several others. Prices are similar to physical SIMs or slightly higher depending on the provider.

Advantages:

• Set up before you leave, nothing to do on arrival
• No physical SIM needed, no swapping cards
• Some phones allow the local SIM to remain active simultaneously (dual SIM)

Drawbacks:

• Requires an eSIM-compatible phone (verify before purchasing)
• Quality varies by provider — some use less extensive networks
• Harder to troubleshoot if something goes wrong

Pocket WiFi

A pocket WiFi (also called a mobile WiFi router) is a small device that creates a local WiFi network for multiple devices to connect to simultaneously. It is rented by the day — collected at the airport on arrival and returned before departure.

Well-known rental services include Ninja WiFi, Global WiFi, IIJmio WiFi, and Mobal. All are booked online and collected at airport counters.

Advantages:

• Multiple devices connected at once — ideal for groups or families
• Useful if you carry a tablet, WiFi camera, or laptop in addition to your phone
• No changes needed to your phone settings

Drawbacks:

• An extra device to charge and carry
• If the battery dies, you lose all connectivity
• More expensive than a SIM for solo travellers (¥500–900/day for most services)
• Must be returned — early morning departures require leaving it in a drop box

Which to choose

Solo traveller or couple with eSIM-compatible phones: eSIM is the most convenient. Set up before leaving and nothing to do on arrival.

Solo traveller with a phone that doesn’t support eSIM: physical tourist SIM at the airport. Simple and cheap.

Family or group of 3 or more: pocket WiFi becomes cost-effective if everyone wants a connection. Compare the cost of one SIM per person against renting a single router.

Very short trip (3–4 days): any of the three works — the price difference between them is small for a few days.

Free WiFi in Japan

It exists, but is not as widespread or reliable as in Europe. Airports, major stations, and convenience stores have free WiFi, and many tourist cities have municipal networks. The drawback is that they require registration or have time and speed limits. They work for occasional browsing; using them as your only connection throughout a trip is not practical.

Making calls during your trip

Tourist data SIMs don’t include calls. If you need to call a Japanese number — to confirm a reservation or contact a ryokan — your options are WhatsApp or LINE if the other party uses them, or Google Voice / Skype for outgoing calls. In practice, most communication with hotels and restaurants happens by email or through the booking platform.