Japan eSIM for a 5-day trip: how much data from a single base

How much data 5 days in Japan takes

What a five-day Japan trip looks like

Most Thai travellers on five days follow one pattern: fly into Tokyo or Osaka and stay in the same city throughout. The first and last days are eaten by airport transfers and check-in or check-out, which leaves roughly three and a half full days of sightseeing. One city is enough, and not changing hotels also saves the data you would spend on cross-city route planning.

A typical shape is four nights in Tokyo: one day in Shinjuku and Shibuya, one in Asakusa and Skytree, and one outing beyond the city such as Kamakura or Kawaguchiko. From Osaka the equivalent is a day return to Kyoto or Nara. Neither requires changing hotels.

Where the data goes in these five days

Per the estimate table, five days comes to roughly 3 GB for light use, 6 GB for normal and 11 GB for heavy. It is not spread evenly. The day trip out of town usually costs the most, because you keep navigation open, check train times and post video on the way. A day walking an old quarter like Asakusa barely touches data beyond opening the map.

• On Tokyo or Osaka trains and subways, signal underground is generally usable, so you need to pre-download little, but save long videos for the hotel.
• Entry tickets sent as QR codes, such as timed bookings at popular museums or attractions, should be saved as screenshots so you are not waiting for a page to load at the gate.
• Camera translation of Japanese menus and signs uses more data than you might expect if you do it often. Download the Japanese language pack for offline use.

Which plan shape suits five days in Japan

Japan fixed packs come in 3, 5, 10, 20 and 50 GB on 30-day validity, plus 0.5 and 1 GB on 7 days and a 3 GB pack on 15 days. None is shaped to fit five days exactly. A normal user needing about 6 GB can take the 10 GB, 30-day pack, which leaves headroom for the day trip. A light user at about 3 GB is fine with the 5 GB pack.

Daily plans for Japan run from 0.5, 1, 2, 3, 5 up to 10 GB a day, and once you pass that day's quota the speed is reduced rather than cut off. The reduced rate differs by version, so read it on each plan page. Over five days, a 1 GB daily plan suits someone who mostly opens maps, and 2 GB suits someone posting photos and video every day. It is the better fit than a big fixed pack when you know you will not exceed about 2 GB on any day.

Install before you fly, switch on when you land

Spend a few minutes at home scanning the QR code and installing the eSIM on stable Wi-Fi, then switch it on when you land at Narita, Haneda or Kansai. In the airport you can open maps and plan the train into the city straight away, without hunting for airport Wi-Fi or queueing for a SIM at a counter. On a five-day trip, every hour saved counts.

A common slip for Thai travellers is bank OTP codes that arrive by SMS. Our eSIM is data only, with no phone number and no SMS, so keep your Thai SIM switched on to receive OTPs. Turn off data roaming on that SIM, set mobile data to use the Japan eSIM, and check the terms for receiving SMS abroad with your operator before you leave.