For years, renting a pocket Wi-Fi router at the airport was how most visitors stayed online in Japan. Today most phones take an eSIM, which puts the data plan straight on the phone. Both work well. They suit different trips.
How each one works
Pocket Wi-Fi is a small battery-powered router. You rent it online, pick it up at the airport or your hotel, carry it with you, and connect your phone to it over Wi-Fi. You return it by post or at a counter when you leave.
An eSIM is a data plan you download onto your phone before you fly. There is no device to collect or return. Your phone connects to a Japanese mobile network directly, and your usual SIM stays on for calls and texts.
Side by side
| eSIM | Pocket Wi-Fi | |
|---|---|---|
| Setup | Five minutes, before you fly | Collect on arrival, return on departure |
| Extra device | None | Router and charger to carry |
| Battery | Your phone's | The router's, typically a day of use, plus your phone's |
| Sharing | One phone, or hotspot from it | Several devices at once |
| Lose it or forget to return it | Nothing to lose | Fees for late return, loss or damage |
| Works if you split up | Yes, each phone is its own | Only near the router |
| Needs an eSIM-ready, unlocked phone | Yes | No |
When an eSIM is the better choice
- You travel alone or as a couple.
- You will split up during the day, or travel between cities at different times.
- You land late, or at an airport where you would rather not queue at a rental counter.
- You do not want another device to keep charged.
When pocket Wi-Fi still makes sense
- A family or group sharing one connection across many devices, including laptops and tablets.
- A phone with no eSIM, or one locked to a carrier (check yours).
- Heavy laptop use where one router for everyone is simpler than several hotspots.
An eSIM can also share its connection: turn on your phone's personal hotspot. It drains your phone faster, and some plans limit hotspot use, so check the plan.
Travelling somewhere other than Japan? Best pocket WiFi for international travel compares renting a router, buying your own hotspot and using an eSIM, with what a family pays for 10 days.
Coverage in Japan
Japan has four main mobile networks: NTT Docomo, KDDI (au), SoftBank and Rakuten Mobile. Coverage in cities and along the main train lines is excellent on the first three. Both travel eSIMs and pocket Wi-Fi rentals ride on these same networks, so the question to ask any provider is which network it uses, not which product type it is.
Tips for Japan
- Install the eSIM at home on Wi-Fi, on the day you leave, before you go to the airport. On most plans the days start when the eSIM first connects in Japan, and each plan states its rule.
- Switch data roaming on for the eSIM line when you land, and keep it off on your home SIM.
- Long underground stretches on some subway lines can drop the signal briefly on any network.
- Free Wi-Fi in stations and convenience stores often needs a registration step. A data plan means you never need it.