Free tool
Will I haveINTERNETwhere I'm going?
Pick your destination and what you plan to do online. You get what NTT docomo states for that place, whether it handles what you need, and the caveats worth knowing.
What to expect
Expected network
NTT docomo names 5G here
NTT docomo lists 5G at this place, usually at a named spot such as the station, not across the whole city. In practice you move between 5G and 4G as you walk: docomo says a 5G area can drop to 4G indoors or with a weak signal, and your phone picks the faster network on its own.
For what you are doing
Maps, messaging and browsing work comfortably on both 4G and 5G here.
Worth knowing
- An indicative guide built from NTT docomo's published spot lists and area notes, not a live coverage feed and not measured by Goodbars. docomo says its area map is computed and may differ from real reception, and service can fail in tunnels, underground and inside buildings.
Your Goodbars Japan eSIM has you online the moment you land. Plans from €12.99. See eSIM plans
Common questions
Does Japan have 5G?
Yes. NTT docomo launched 5G on 25 March 2020, and Japan's regulator, MIC, put docomo's 5G population coverage at 89.4% at the end of March 2025. docomo's published 5G spots cluster around big stations and city centres; everywhere else your phone uses 4G/LTE.
Is 4G fast enough in Japan?
For almost everything, yes: 4G/LTE handles maps, messaging, social media, streaming and video calls. docomo itself notes that some of its 5G on older 4G bands runs at 4G speed, so the label matters less than the signal.
Will I have signal on the shinkansen?
Japan's regulator reported in November 2020 that mobile coverage was complete on every shinkansen section then in service, while warning of weak spots where a connection can drop depending on carrier and phone. docomo does not claim continuous 5G on board, so download what you need before a long leg.
Is there signal in the mountains and on remote islands?
Often, but not everywhere: docomo says mountains, remote islands and the sea still have places its ground stations do not reach. Download maps and tickets before hiking or taking a ferry.
Will my eSIM switch between 5G and 4G automatically?
Yes. Your phone connects to the fastest network available and moves between 5G and 4G on its own; there is nothing to change. docomo notes the 5G icon can show on standby while data actually runs on 4G.
Why is my connection slow at New Year or a big event?
docomo says the network can get congested at New Year, during disasters and at events, when many people use the same area. Waiting out the peak or moving a little usually helps more than changing settings.