Saily
1 GB · 7 days
$3.99$3.99/GB
See this planChoosing an eSIM for 1 day is mostly about validity and volume. With at least 1 GB over 1 day, the cheapest option we found is Saily at $3.99, and Saily scores best overall.
Updated September 24, 2026Prices checked September 24, 2026
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1 GB · 7 days
$3.99$3.99/GB
See this planUnlimited · 1 day
$4.20
See this plan1 GB · 7 days
$3.99$3.99/GB
See this planPlan shown: the cheapest plan of each provider that covers at least 1 day and 1 GB. Tap a column header to sort.
| Provider | Data | Validity | Price | Price/GB | Japanese network | 5G | Hotspot | Score | CTA |
|---|---|---|---|---|---|---|---|---|---|
| Saily | 1 GB | 7 days | $3.99 | $3.99/GB | KDDI/SoftBank | Yes | Yes | 9.8 | View plan |
| Airalo | 1 GB | 3 days | $4.00 | $4.00/GB | SoftBank/KDDI | Yes | Not stated | 9.2 | View plan |
| Yesim | Unlimited | 1 day | $4.20 | — | KDDI | Yes | Yes | 9.1 | View plan |
| Holafly | Unlimited | 3 days | $11.90 | — | KDDI/SoftBank | Yes | Yes | 6.4 | View plan |
| Drimsim | 1 GB | Pay as you go | $23.10 | $23.10/GB | Not published | Not stated | Not stated | 3.4 | View plan |
Plan for this page: 1 GB · 7 days
Plan for this page: 1 GB · 3 days
Plan for this page: Unlimited · 1 day
Plan for this page: Unlimited · 3 days
Plan for this page: 1 GB · Pay as you go
On a short stay of 1 day, most travelers use their phone for maps, train times, translation and messaging. With the assumption used on this site that is around 1 GB in total, so a small plan is enough and an unlimited plan rarely pays off.
Providers sell plans in fixed lengths, so the plan picked for each provider may last longer than your trip. That is not a problem: you simply stop using it when you leave. What matters is the price for the volume you need.
If your 1 day are a stopover or a layover in Tokyo or Osaka, install the eSIM before the flight so you are online as soon as you clear immigration. Short trips leave no time to hunt for Wi-Fi.
Every price on this page is the one published for Japan on the date shown at the top, in US dollars as the provider displays it; the final amount is the one shown at the provider’s checkout.
Pick your trip length and how you use your phone. The assumptions are visible and editable.
Buy the plan before you leave and keep the QR code or the app handy.
Install the eSIM at home on Wi-Fi. Most plans only start the validity period once the eSIM connects in Japan.
On landing, switch the eSIM on for mobile data and keep your home SIM for calls and texts if you need them.
Turn on data roaming for the eSIM line, then check that the phone shows a Japanese network.
Your phone must be carrier-unlocked and eSIM-compatible. Check this in your phone settings before you buy.
With this site’s assumptions a light user needs about 0.3 GB a day and a medium user about 0.8 GB. For 1 day the plans shown here carry at least 1 GB; use the estimator to adjust.
Among the plans that last at least 1 day and cover at least 1 GB, the cheapest is Saily at $3.99. Prices were checked on September 24, 2026.
On today’s published prices Saily ranks first for 1 day, at $3.99. The score weighs price, Japanese network, hotspot and options; the formula is explained under the ranking.
Many unlimited plans apply a fair-use rule and slow the speed after a daily threshold. Read the plan conditions on the provider’s page; Yesim currently has the cheapest unlimited option here at $4.20.
Select the eSIM as your mobile data line, turn on data roaming for it, and wait for a Japanese network name to appear. If nothing happens, restart the phone and check the APN settings shown by the provider.
Most travel eSIMs sold for Japan are data only. You can still call through apps such as WhatsApp or FaceTime, and keep your home SIM active for texts.
We compare the plans each provider publishes for Japan. We do not rank on personal testing or user reviews. For each provider we take the cheapest plan that covers the need of this page, then compute a score out of 10:
At equal score, providers we have a partner link with are listed first. Prices change often, so check the final price on the provider’s site.