The Best eSIMs for Unlimited Data in Japan

Whether you're staying for just a few days or for several weeks, choosing the right eSIM for Japan can make your travel stress-free. From quick business trips to ski holidays, we have a plan for every traveller.

Stay connected with all the data you need, and reliable coverage on fast networks like KDDI and NTT Docomo.

Sim Local only partners with trusted networks like au Japan to give you that ‘just like home’ connection — wherever you are. 

1. You can activate one instantly, anywhere: eSIMs can be activated as soon as you land, saving you the hassle of finding a local SIM card or dealing with physical cards.
2. Stop worrying about roaming charges: With a few taps of your phone settings, you make the quick switch to a pay-as-you-go plan during your trip and stop relying on your home plan's data roaming. 
3. Your phone probably supports eSIM: Most smartphones are compatible with eSIM technology nowadays. So it makes it easier to travel.

Here's our list of the best eSIMs for Japan depending on your length of stay. au by KDDI is one of Japan’s biggest and most reliable mobile networks, known for excellent nationwide coverage and fast data speeds — especially outside the big cities where some networks drop off.

Unlike international providers like Holafly or Ubigi, you’re connecting straight to the source for faster, stronger coverage at cheaper prices!

Some travellers, especially from nearby Asian countries, often take shorter trips to Japan and stick to just one or two cities, like Tokyo or Osaka. If that sounds like you, check out our eSIM plan below. 👇

Japan Unlimited: 4-Day eSIM

Unlimited eSIM

Japan

AU

Duration

4 Days

Plan

Data

Speed

4G / 5G

Price

$13.00

More Info

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Japan's 5G You Can Trust

Top Seller

Stay online during your short visit to Japan with this 4-day eSIM plan from au by KDDI, priced at $13 USD. Enjoy unlimited data on one of Japan's most popular networks, plus 3GB for data tethering if you need to share your connection.

Most first-time visitors to Japan spend at least a week in the country, typically dedicating a few days to exploring Tokyo and its iconic neighborhoods, such as Shibuya, Shinjuku, and Asakusa. Kyoto is often included on the list as well, famous for its temples, shrines, and traditional culture, which usually takes another two to three days to fully experience.

Japan Unlimited: 10-Day eSIM

Unlimited eSIM

Japan

AU

Duration

10 Days

Plan

Data

Speed

4G / 5G

Price

$26.00

More Info

Buy Now

Japan's 5G You Can Trust

Best Value

For $26, this 10-day eSIM from au by KDDI gives you unlimited smartphone data while you explore Japan. It also allows tethering up to 3GB on the KDDI network.

With two weeks in Japan, you can take it easy and see more than just Tokyo, Kyoto, and Osaka. Places like Hiroshima and Miyajima are worth a visit, and depending on the season, you could head up to Hokkaido for skiing or down to Okinawa for beaches.

Japan Unlimited: 15-Day eSIM

Unlimited eSIM

Japan

AU

Duration

15 Days

Plan

Data

Speed

4G / 5G

Price

$39.00

More Info

Buy Now

Japan's 5G You Can Trust

Top Seller

Stay connected in Japan with this $39 eSIM plan. It gives you unlimited data for 15 days and uses the KDDI network. You can also share up to 3GB as a hotspot, making it easy to stay online during your trip.

If you’re staying in Japan for three weeks to a month, you can really take your time exploring the culture, history, and natural beauty. Explore beyond the usual places and visit Kyushu, with its hot springs in Beppu and volcanoes; Shikoku, known for the Shikoku Pilgrimage and beautiful scenery; or Tohoku in the north.

Japan 20GB: 30-Days eSIM

20 GB eSIM

Japan

Smartroam

Duration

30 Days

Plan

Data

Speed

4G / 5G

Price

$88.25

More Info

Buy Now

Stay Connected, Anywhere.

Stay connected in Japan with this 20GB eSIM plan for 30 days. Even though it’s not unlimited, it’s perfect for travellers staying three weeks or more. It works on 4G and 5G networks all over the country, including Tokyo, Kyoto, and Osaka. Setup is easy. Just scan the eSIM and you’re ready to go. You can use it for maps, streaming, messaging, and even hotspot sharing.

Most modern smartphones (like iPhone XR and newer, Pixel 3 and newer, Samsung Galaxy S20/S21/S22 series) support eSIMs. Always check your phone's specifications before purchase.

Simply tap DOWNLOAD or scan the QR code you receive after purchase, follow the prompts in your mobile settings, and select the new eSIM profile as your data line. Activation takes just three minutes.

No. As long as you disable your home SIM’s data roaming and select your eSIM as the active data line, your usage will stay on the Japan eSIM without incurring roaming fees.

Yes. The au by KDDI plans include up to 3 GB of tethering data, so you can share your connection with a laptop or other devices.

Check that your eSIM is active, restart your device, manually select the "au" or "KDDI" network if needed, and ensure APN settings are correct. Still stuck? Speak to someone on WhatsApp.

The cheapest way to use your phone in Japan is to get a local eSIM. This way, you can use data and make calls without paying high roaming fees. You can buy it online before you go, so you’re connected as soon as you land.

Yes! As long as your eSIM has data or you're connected to Wi-Fi, WhatsApp will work just like normal. You can message, call, and share without any issues.

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