Japan eSIM guide: networks, coverage and setup
Japan has four mobile networks with dense coverage in cities and on trains. Travel eSIMs are almost always data-only, so you will not get a Japanese phone number.
Get an eSIM
Local networks
- NTT DocomoLargest network with the widest coverage, including rural and mountain areas.
- au (KDDI)Nationwide coverage comparable to Docomo; also hosts Rakuten roaming in some areas.
- SoftBankNationwide network, strong in cities.
- Rakuten MobileNewest operator; claims 99.5% population coverage including roaming on au.
5G5G is available in major cities and many urban areas on all four networks; 4G LTE covers most of the country. All 3G networks are now shut down (Docomo's FOMA ended 31 March 2026).
Must-knows
- No Japanese number: apps or services that send SMS codes to a Japanese number will not work; most taxi apps accept a foreign number, but check before you rely on one.
- From 1 April 2026, Japan's carriers run 'JAPAN Roaming', an emergency cross-network roaming service used during major outages or disasters.
- Free public Wi-Fi is common at stations and convenience stores, which helps if your data runs low.
Buying a local SIM
Data-only SIMs are sold at airports and electronics stores. Voice SIMs with a Japanese number generally require a Japanese address and residence card, so short-term visitors rarely get one. A law amended in May 2026 will also require ID checks (passport number for visitors) for data-only SIMs; it takes effect by May 2027.
Weak-signal areas
Signal is strong in cities and on the Shinkansen. Deep mountain areas, some hiking trails and remote islands can have weak or no signal, where Docomo usually reaches furthest.
How much data do you need?
Pick a plan of about 3.6 GB