eSIM vs pocket WiFi vs SIM card for Japan: which one to get
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For most visitors from the US, the answer is an eSIM bought before you fly. It costs less than roaming, there is nothing to pick up or return, and it works the moment the plane lands. The other two options still make sense in a few specific cases, listed below.
The three options side by side
| eSIM | Pocket WiFi | Physical SIM | |
|---|---|---|---|
| Pick-up | None. QR code by email | Airport counter or hotel delivery | Airport counter, vending machine or mail |
| Return | None | Mailbox or counter before you leave | None |
| Shares with a group | Hotspot, drains your battery | Yes, built for it | Hotspot, drains your battery |
| Extra device to charge | No | Yes | No |
| Phone must be unlocked | Yes | No | Yes |
| Keeps your US number active | Yes, on the other SIM | Yes | Only on a dual-SIM phone |
Check these two things first
- Is your phone unlocked? Phones bought on a payment plan from a US carrier are often locked until paid off. On an iPhone, look under Settings, General, About, Carrier Lock. If it does not say “No SIM restrictions”, an eSIM from another company will not work, and pocket WiFi is your option.
- Does your phone support eSIM? iPhone XS and later do. Most recent Pixel and Galaxy phones do. Budget Android phones often do not.
When pocket WiFi is the better choice
- Three or more people who will stay together all day. One device, one bill.
- A locked phone, or travelers with tablets and laptops that have no SIM slot.
- Heavy use, such as uploading video every day. Rental routers are sold with large or unlimited allowances.
The trade-off is logistics. You carry and charge a second device, and it has to go back in a mailbox or to a counter before your flight. If the group splits up, only one half has data.
If you go this way, Sakura Mobile is a Japanese provider that rents pocket WiFi and sells travel SIMs and eSIMs, with sign-up and support in English.
When a physical SIM makes sense
Mainly when your phone is unlocked but has no eSIM support. You can order one ahead or buy at the airport. Expect to enter APN settings by hand on some Android phones.
Which eSIM
All travel eSIM brands resell access to Japanese networks, so the differences are price, plan sizes and the app. Two that list Japan plans:
Compare the plan that matches your trip length on each. A week of maps, messaging and restaurant searches uses far less data than most people expect; video is what burns through an allowance.
Setting it up
- Buy the plan a day or two before departure.
- Install it at home while on WiFi. Do not delete it afterwards; most can only be installed once.
- Leave it switched off until you land, then turn on the eSIM line and enable data roaming for that line only.
- Turn data roaming off on your US line so your home carrier does not bill you.
What about free WiFi?
Stations, convenience stores and cafes in Tokyo have it, but each network wants a sign-up and it drops as soon as you walk away. It is fine as a backup, not as a plan for finding your way around.