Staying connected in Japan.

Because coverage is not a problem here, the whole decision is price. Roaming on your US plan is the expensive default: AT&T and Verizon day passes run about 10 to 12 dollars a day, so a week is roughly 70 to 84 dollars and a two-week trip approaches 170. T-Mobile is the exception worth checking first: its current tiers include a genuine high-speed allowance abroad, roughly 5GB on Experience More, Magenta MAX and Go5G Plus, 15GB on Experience Beyond and Go5G Next, and 30GB on Better Value, slowing to 256kbps only once that is used up. The entry Essentials tier is the one throttled from the start. Google Fi and Visible set their own terms, so read your own plan rather than assuming. That matters more in Japan than in most places, because you will lean on maps and transit apps constantly to navigate a rail network with more exits per station than some towns have streets, and a throttled 256kbps connection handles that badly.

The thing not to do is roam with no plan. Pay-per-use data runs about 2 dollars a megabyte, thousands per gigabyte, and background app activity alone can run a bill up before you have opened anything, so turn off data roaming until an eSIM or a pass is active.

A travel eSIM is the cheapest way for most visitors to get real data in Japan. A Nomad eSIM is a few dollars per gigabyte, well under day-pass pricing, and it activates before you fly and works from landing, with no counter to find at Narita or Kansai after a long flight. Your US number stays reachable on your normal plan while the eSIM carries the data. Since Japanese networks are strong across the board, which one the eSIM rides is not something you need to research the way you would in Australia.

Japan's traditional answer was the rented pocket wifi box, reserved in advance and collected at the airport. It still exists and it still makes sense for a family or a group sharing one connection, but for one or two people an eSIM is cheaper and simpler: nothing to collect, nothing to return, nothing extra to charge each night, and no deposit. Free wifi is also widespread in stations, convenience stores, cafes and hotels, which is a useful backstop but not a plan, since it usually wants a sign-in and rarely follows you onto a train.

This section is short because there is little to warn you about. Japan has 4G almost everywhere, including on the shinkansen at full speed, in most rural and mountain areas, and in the long tunnels that would break the signal elsewhere, with 5G growing across the cities. Deep in the mountains or far out on a small island you may find a thin patch, and it is not the sort of thing most itineraries need to plan around.

One practical note that is about money rather than signal: Japan still runs on cash more than most rich countries, and having working data is what lets you find the right ATM, read a menu, buy rail tickets in an app and top up an IC card without guesswork, which is a real reason not to travel here on a throttled roaming connection. This guide is written for US travelers departing the US. For more, see cash or card in Japan, taxis and apps in Japan, and the Japan money guide.

Common questions

Quick answers.

More on Japan

The little money things nobody warns you about.

• Taxis in Japan, and the GO appJapanese taxis are spotless, honest and metered, with doors that open for you and no tipping ever. They are also pricey, so from the airport the train usually wins. Here is how it works.
• Do I need cash in Japan, or can I use cards?Short answer: bring some cash, but you will tap and swipe for most of a city trip. The catch is that most Japanese bank ATMs reject foreign cards. Here is where to get yen, when you truly need it, and how to pay for the rest.
• Bringing your dog or cat to Japan.Japan is one of the long-lead destinations. Two numbers decide everything: the lead time, which is 7 to 8 months because of a fixed 180-day wait you cannot shorten, and the all-in cost, which runs into the thousands. Miss the sequence and the clock resets. Here is the order, the official route, and what to budget.
• Tipping in JapanThe answer here is simple and genuinely freeing: do not tip. Japan has no tipping culture, nobody expects one, and leaving extra money can cause confusion rather than gratitude. A polite thank-you is all that is needed.
• Do US citizens need a visa for Japan?Short answer: no, for stays up to 90 days, and there is nothing to apply for. Japan is one of the easiest countries for Americans to enter. Here is what you actually need, what Visit Japan Web does, and the change that is coming but is not here yet.
• Do you need a Japan Rail Pass?For years the answer was a reflexive yes. Since the 2023 price jump it is usually no, and the honest test is arithmetic you can do in about a minute before you spend anything.