For a typical trip to Japan, the useful shortlist is simple: choose a fixed-data plan if maps, messages and train apps are your main needs; pay for unlimited data only if you stream, work or tether heavily.
Quick verdict
- Best fixed-data value checked: Saily, 20 GB for 30 days at $24.99. Airalo is essentially tied at $25, and names SoftBank and KDDI as its Japanese networks.
- Best checked seven-day unlimited price: Maya at $19.99, but it auto-renews while Travel Mode is on. Turn it off after the trip.
- Best for transparent hotspot use: Holafly states 1 GB per day of sharing; Saily and Yesim state hotspot support without a numerical destination limit.
- Best if named networks matter: Airalo and Holafly both disclose SoftBank and KDDI.
Japan eSIM prices compared
| Provider | Useful verified plan | Network / speed | Hotspot | Condition to know |
|---|---|---|---|---|
| Airalo | 20 GB / 30 days — $25 | SoftBank + KDDI | Not verified | Unlimited offer shown at 1 Mbps after 3 GB/day |
| Holafly | Unlimited / 7 days — $27.50 | KDDI + SoftBank, 5G/4G/LTE | 1 GB/day | Fair-use slowdown may last up to one day; threshold not stated |
| Saily | 20 GB / 30 days — $24.99 | Local partner not named, 3G–5G | Stated as unlimited | Unlimited: 5 GB/day at full speed, then up to 1 Mbps |
| Maya | Unlimited / 7 days — $19.99 | Strongest available network, 5G/4G | Included | Auto-renews while Travel Mode remains on |
| Yesim | 20 GB / 30 days — $27 | Automatic fastest network, including 5G | Included | Unlimited fair-use threshold and reduced speed not disclosed |
These are representative plans, not the only choices. The five providers also sell lighter, longer or unlimited options. Prices were recorded directly from their official Japan pages; discounts may disappear.
Choose by how you will use data
For a week of navigation, translation, messaging and occasional social media, 3–5 GB is usually the sensible range. Airalo showed 3 GB for seven days at $8 and 5 GB at $10. Saily’s $3.99 plan has only 1 GB, so it suits very light use.
For two to four weeks with daily browsing and photo uploads, compare 10–20 GB. Saily and Airalo were almost identical at 20 GB/30 days. Airalo’s advantage is network disclosure; Saily’s is unrestricted hotspot sharing as stated on its page.
For work calls, video and heavy tethering, compare unlimited plans by their actual rule. Saily drops to up to 1 Mbps after 5 GB in a day. Airalo displayed 1 Mbps after 3 GB/day on its unlimited offer. Holafly may apply a temporary fair-use restriction without publishing a threshold. Yesim also warns of a daily threshold but does not quantify it.
Network, hotspot and calls
Japan’s city routes are well covered, but the provider’s partner network still matters on rural rail lines, in mountain areas and across Hokkaido or Okinawa. Airalo and Holafly name SoftBank and KDDI. Saily, Maya and Yesim describe automatic or local network selection without naming the carrier on the Japan page.
All five options are primarily for mobile data. Do not expect a Japanese phone number. Use WhatsApp, LINE, FaceTime or another internet calling app. Saily sells a separate phone-number/minutes option; Maya can carry your home number over Wi-Fi Calling only when your home carrier supports it, and that carrier may still charge.
Install before landing
First, confirm that the exact phone model supports eSIM and is carrier-unlocked. Install over reliable Wi-Fi before departure, keep the QR code or manual details offline, and leave the plan switched off until the provider’s activation step.
After landing, select the travel eSIM for mobile data and enable data roaming on that eSIM. Airalo and Holafly start validity when the plan connects in Japan. Saily activates automatically on arrival when its eSIM and roaming are enabled. Maya and Yesim are activated from their apps.
FAQ
Can I keep my normal number?
Yes. Keep your primary SIM for your number and use the eSIM for data. Disable data roaming on the primary SIM to reduce the risk of home-carrier charges.
Is unlimited data really unlimited in Japan?
Total data may be unlimited, but full-speed data often is not. The verified pages showed daily fair-use rules or possible throttling for Airalo, Holafly, Saily and Yesim. Maya currently claims no caps or throttling; treat that as the provider’s published condition and recheck it at checkout.
When should I buy the eSIM?
Buy and install before departure while you have stable Wi-Fi, but follow the provider’s activation rule. Saily also states a 30-day activation window, so buying months too early is not useful.
Continuing through Asia?
Compare the future guides for South Korea eSIM, China eSIM and Thailand eSIM before choosing a regional plan instead of separate country plans.