Best eSIM for Japan (2026): prices for every trip length

The "best" eSIM for Japan is the cheapest plan that covers your days and your data use – not the one with the most features. Below we compare 29 Japan plans from Airalo and Saily with prices from our database (last checked: Airalo 2026-10-13, Saily 2026-10-12), then show which one to pick for 3-day, 1-week, 2-week and month-long trips.

Our picks (prices as of Airalo 2026-10-13, Saily 2026-10-12)

• Cheapest overall: Saily 1 GB / 7 days for US$3.99
• Best for a typical 1-week trip: Airalo 5 GB / 7 days for US$10.00
• Best unlimited for a week: Airalo Unlimited / 7 days for US$26.50
• Best for 2+ weeks: Airalo 10 GB / 15 days for US$17.50

How much data do you need in Japan?

Most travellers buy far more than they use. A rough guide per day:

How you use your phone	Data per day	7 days	14 days
Maps, messaging (LINE/WhatsApp), occasional browsing	0.3–0.5 GB	3 GB	5–7 GB
+ Instagram/TikTok, photo uploads, some YouTube	1–1.5 GB	7–10 GB	15–20 GB
Streaming video, video calls, hotspot for a laptop	3 GB+	unlimited	unlimited

Google Maps navigation and train apps such as Navitime use very little data. Video is what eats your plan – an hour of HD streaming can use 1–3 GB. If you're unsure, buy a smaller plan and top up in the app if you run low.

Best eSIM for Japan by trip length

3–5 days (weekend in Tokyo, stopover)

For a short trip, a small fixed-data plan is the cheapest option: Saily 1 GB / 7 days for US$3.99. If you want unlimited for a few days, Airalo's 3-day unlimited costs US$11.50; Saily's shortest unlimited plan is 5 days, for US$18.99.

1 week (the classic Tokyo–Kyoto–Osaka trip)

For a week of maps, social media and some video, around 5 GB is usually enough: Airalo 5 GB / 7 days for US$10.00. Heavy users should compare the 7-day unlimited plans – Airalo US$26.50, Saily US$26.99.

2 weeks

Two weeks is where fixed-data plans shine – you pay for the gigabytes, not the days: Airalo 10 GB / 15 days for US$17.50. Unlimited for 15 days costs US$48.00 with Airalo and US$48.99 with Saily.

3 weeks to a month

For long stays, 20 GB for 30 days from US$25.00 (Airalo) or US$24.99 (Saily) covers most people. If you work remotely, 30-day unlimited costs US$69.00 (Airalo) or US$71.99 (Saily).

Airalo vs Saily at a glance

Both run on SoftBank and KDDI with 5G where available, so coverage is similar. The main difference is the unlimited speed limit: Airalo slows to 1 Mbps after 3 GB a day, Saily after 5 GB a day. Read the full Airalo vs Saily Japan comparison.

(Figures stated by the providers, checked 2026-10-02.)

What to check before you buy

• Your phone is unlocked and supports eSIM. Most iPhones from the XS onwards and recent Pixel/Samsung models do, but carrier-locked phones won't accept a foreign eSIM.
• "Unlimited" has a daily full-speed limit. After it you drop to around 1 Mbps – fine for maps and chat, slow for video.
• Data-only means no Japanese phone number. You can still call and message over WhatsApp, LINE, FaceTime and iMessage. Restaurants and hotels that ask for a phone number will usually accept your home number.
• Validity starts in Japan, not when you buy. Both Airalo and Saily start counting days when the eSIM connects in Japan, so you can install at home.
• Rural trips. Both providers use SoftBank and KDDI; coverage is strong in cities and along train lines, patchier deep in the mountains. Download offline Google Maps for hiking areas.

eSIM vs pocket Wi-Fi vs SIM card in Japan

• eSIM: cheapest and instant – no pickup or return, works the moment you land. Best for most travellers with a recent phone.
• Pocket Wi-Fi: one device shared by a group, but you must collect and return it, charge it every day and carry it everywhere. Worth it mainly for groups of 3+ with older phones.
• Physical SIM: useful only if your phone has no eSIM support; you'll need to pick it up and swap SIMs.

How to set up your Japan eSIM

1. Buy your plan and install it at home on Wi-Fi, a day or two before you fly.
2. In your phone's cellular settings, label the new line "Japan".
3. On landing at Narita, Haneda or Kansai, set mobile data to the Japan eSIM and turn on data roaming for that line only.
4. Keep your home SIM switched on for calls/SMS if you need them, but make sure data roaming is off on it to avoid charges.
5. No signal? Toggle airplane mode, then check the APN settings in the provider's guide.

FAQ

What is the cheapest eSIM for Japan?

As of Airalo 2026-10-13, Saily 2026-10-12, the cheapest Japan plan we track is Saily 1 GB / 7 days for US$3.99.

How much data do I need for 7 days in Japan?

About 3 GB for maps and messaging, 5–10 GB if you use social media and some video, and unlimited if you stream or share a hotspot.

Is an unlimited eSIM worth it in Japan?

Only for heavy users. Unlimited for 7 days costs around Airalo Unlimited / 7 days for US$26.50, while a 5 GB plan that lasts a week is Airalo 5 GB / 7 days for US$10.00. Unlimited plans also slow down after a daily allowance (3 GB on Airalo, 5 GB on Saily).

Can I keep WhatsApp and my number with a Japan eSIM?

Yes. A travel eSIM is data-only and works alongside your normal SIM, so WhatsApp and iMessage keep your number.

Does a Japan eSIM work on the Shinkansen?

Both Airalo and Saily use SoftBank and KDDI, which cover the main Shinkansen routes. Expect short drops in long tunnels.

When should I buy and install my Japan eSIM?

Buy and install it before you fly, on Wi-Fi. The plan only starts counting days when it connects in Japan.