Japan is the country where being offline hurts most. Train transfers change platform at short notice, restaurant menus reward a camera translation, and the addresses are numbered by block rather than by street, so a map is not optional.
Free Wi-Fi exists, and it is not enough
Convenience stores, stations, many cafés and most hotels have free Wi-Fi. Between those points you have nothing, and between those points is exactly where you need directions. Several networks also want an email registration through a captive portal, which is awkward when you have no data to receive the confirmation.
Treat Wi-Fi as a bonus for big downloads, not as your connection.
The options on the ground
Pocket Wi-Fi rental. A small router you collect at the airport and post back at the end. Good for a group sharing one connection. You are carrying and charging a second device, and you pay for the days you booked whether you use them or not.
A prepaid tourist SIM. Widely sold at airport counters and electronics shops. Cheap per gigabyte, but it takes your SIM slot, so your own number goes away for the trip.
A travel eSIM. Installed before you fly, active the moment you land, with your usual number still in the phone for calls and messages. The trade-off is that travel plans carry data only, and your phone has to support eSIM.
How much data a Japan trip uses
Navigation, translation, messaging, train apps and photo sharing. For most people that is 200 to 500 MB a day, so a week runs comfortably on 3 GB. Add data if you plan to stream on Shinkansen journeys or take long video calls home. Our guide to sizing a plan breaks it down by activity.
Set it up before you fly
- Check that your phone takes an eSIM and is carrier-unlocked. The one-minute check settles it.
- Buy the plan and install the eSIM while you are on Wi-Fi at home. Installing needs an internet connection, and the profile installs only once.
- Leave the line switched off until you land. Validity starts when the eSIM first connects to a Japanese network.
- On arrival, turn the line on, enable data roaming for it, and set it as your data line. Full steps are in the install guide.
Practical notes for Japan
- Coverage is excellent, including on most Shinkansen routes and in the Tokyo and Osaka metro systems. Mountain areas and some rural valleys are the exception.
- Your number still works for SMS two-factor codes, because the home SIM stays in the phone. Watch your carrier’s roaming charges for actual calls.
- IC cards and mobile payments mostly work offline once provisioned, but provision Suica or Pasmo in Apple or Google Wallet before you leave.
- Translation apps are worth downloading with offline language packs, even with a data plan.
Plans for Japan
Live prices, data allowances and validity for every Japan plan we sell are on the Japan eSIM page. The app keeps the eSIM, its QR code, the usage counter and the low-data alert together on your phone.