Best eSIM for Japan

Prices in Japan

Saily and Airalo are a cent apart on 5 GB; Airalo is 49 cents cheaper on a week of unlimited data. How the three providers compare across all fifteen destinations is in our main eSIM comparison.

Which network you get

All three sit on KDDI (au) and SoftBank, never on Docomo:

• Airalo shows SoftBank as its primary network with one other it does not name. No 5G or hotspot statement on the page.
• Saily states KDDI and SoftBank, 5G in major cities including Tokyo, Kyoto and Osaka, and limitless hotspot sharing. Its unlimited plan runs at full speed for 5 GB a day, then 1 Mbps.
• Holafly lists KDDI / SoftBank, 5G where available, and caps hotspot sharing at 1 GB a day.

Buying a local SIM instead

Japan’s big carriers sell few prepaid SIMs to tourists; the market is MVNOs and airport counters.

• IIJ’s Japan Travel SIM is a data-only prepaid SIM in 3 to 55 GB sizes, valid 30 days from activation, and a Japan Travel SIM Unlimited in 10, 15 and 31-day versions on au’s coverage with tethering caps of 9, 14 and 30 GB. Prices are set by each retailer and are not printed on IIJ’s pages.
• Mobal sells a Japan SIM with a phone number on Docomo’s network: ¥4,950 for the SIM and from ¥1,650 a month, with free pick-up at Haneda, Narita, Kansai and other airports. A voice SIM requires the original passport.
• SoftBank’s own Prepaid SIM for Travel is data-only, sold at an open price through SoftBank shops and airport counters, and requires the original passport.
• Narita’s site lists SIM vending machines in all three terminals before passport control, and Haneda’s lists a prepaid SIM counter in the Terminal 3 arrivals lobby open 06:00 to 23:00.

Before you land

The ministry’s guidance is explicit that data-only SIMs are outside the identity-verification law today, and equally explicit that from April 2027 they come inside it, possibly including short-stay visitors. Until then a data SIM or eSIM needs no passport check.

• Install on Wi-Fi at home; Airalo allows 365 days from purchase to start, Saily 180.
• These are data-only plans. Keep your home SIM active for the text messages your bank and your airline send, with data roaming switched off on it.
• Airalo’s page says its Japan eSIM “covers all of Japan, including Okinawa and Hokkaido”.
• Carry your onward reservation in a form that opens without a connection: the check-in desk asks for it before the eSIM is on. Japan’s onward-ticket rules are on their own page, and the free checker covers your passport.