Best trust record · largest daily cap · KDDI and SoftBank
Saily in Japan
Saily has the best support record of anyone here by a wide margin and the biggest daily unlimited allowance among the brands we link. Its networks are KDDI and SoftBank, which is fine in the cities and not the Docomo you want in the mountains.
Every Saily Japan plan
every plan in USD, 2026
| Plan | Price | Per GB | Notes |
|---|---|---|---|
| 1GB / 7 days | $3.99 | $3.99 | GigSky's 1GB is $2.99 for the same week. |
| 3GB / 30 days | $7.99 | $2.66 | Fifty cents over GigSky, and twice the validity. |
| 5GB / 30 days | $10.99 | $2.20 | Yesim is $10.56 and GigSky $10.29 for the same size and window. |
| 10GB / 30 days | $17.99 | $1.80 | A penny under Airalo, $1.20 over GigSky. |
| 20GB / 30 days | $24.99 | $1.25 | Best 20GB with a full month. Airalo's is $24.00 for 15 days. |
| Unlimited / 5 days | $18.99 | $0.76¹ | 5GB a day at full speed, then up to 1 Mbps until midnight local time. Both figures are on Saily's Japan page. ¹ Per-GB assumes you use the full 5GB every day. |
| Unlimited / 7 days | $26.99 | $0.77 | |
| Unlimited / 10 days | $34.99 | $0.70 | |
| Unlimited / 15 days | $48.99 | $0.65 | |
| Unlimited / 20 days | $59.99 | $0.60 | |
| Unlimited / 25 days | $65.99 | $0.53 | |
| Unlimited / 30 days | $71.99 | $0.48 |
Saily has the most granular unlimited ladder in Japan, seven lengths from five days to thirty. That is genuinely useful: a nine-day trip buys ten days rather than being pushed to fifteen. Prices in USD, checked 2026, every plan on Saily's own Japan page, where every plan earns 3% back in Saily credits and no discount was running. Hotspot is allowed with no separate limit stated.
Saily sells the largest unlimited allowance in Japan
5GB a day
Almost nothing sold for Japan is truly unlimited. Nearly every plan with the word on it is an allowance, and the question is only how big the allowance is and what happens when you cross it.
Saily's is 5GB per day. Airalo's is 3GB. GigSky's is 3.5GB. Nomad's is 2GB. Ubigi's 8-day plan is also 5GB a day; its longer plans give a total instead. Yesim does not publish a figure at all. So among the brands we link, this is the most full-speed data per day anyone commits to in writing. The exception to the whole pattern is a local KDDI plan from Sim Local sold with no daily cap, which we cannot link.
Five gigabytes is a real amount. It is roughly five hours of 720p video, or a full working day of a tethered laptop with video calls, or every map, message and photo upload you can generate in a day plus a film in the evening. If you actually use it, thirty days works out at 48 cents a gigabyte, the cheapest full-speed data on this site by some distance.
After 5GB, Saily's Japan page promises "Unlimited data at up to 1 Mbps" for the rest of the day; the allowance resets at midnight local time, per Saily's Terms. That matches Airalo's 1 Mbps; Ubigi gives 2 Mbps. GigSky does not publish its reduced speed, and its high-speed data resumes 24 hours from activation rather than at midnight.
If you are going to buy unlimited anyway, buy the largest published cap. Five gigabytes a day is the biggest number anyone will print for Japan.
See Saily unlimited plans Compare every capWhich Japanese network does Saily use?
KDDI and SoftBank, not Docomo
This site's central argument is that in Japan the carrier behind the eSIM decides whether your trip works, because Docomo, KDDI and SoftBank diverge sharply once you leave the cities. Saily's Japan page now answers the question itself: its eSIM connects to local networks "including KDDI and SoftBank", checked 2026.
That is the same pair Airalo publishes, and it leaves out NTT Docomo. One traveler complaint is still worth knowing: reviewers on esimdb describe Saily's Japan traffic exiting through Hong Kong, which for at least one of them broke ChatGPT and other services that geolocate by exit address. That is a traveler report, not a published fact, and if you rely on a service that cares where your traffic appears to come from, it is worth knowing before you pay.
How much the missing Docomo costs you depends entirely on your route. On the Tokyo to Osaka corridor, close to nothing, because KDDI is excellent along the whole corridor and SoftBank is strong in the metros. In the Alps or rural Hokkaido, it can be the difference between bars and no bars, and the fix is GigSky on Docomo rather than a different Saily plan.
The 4.7 across 32,870 reviews is the best record on this site
and it is earned
Saily is run by Nord Security, the company behind NordVPN, and it shows in the support operation. Trustpilot 4.7 from 32,870 reviews as of 2026, with 83 per cent five-star and replies to 99 per cent of negative reviews, usually within a day.
For comparison, Airalo sits at 4.2 from 48,959, GigSky at 4.3 from 8,403 and Yesim at 4.3 from 2,996. The gap between 4.7 and 4.2 across tens of thousands of reviews is not noise.
Why this matters more than it looks: an eSIM fails at the worst possible moment, in the arrivals hall of a country where you cannot read the error message. The thing you are actually buying, once the prices are within a dollar of each other, is whether someone answers when it does not work.
Saily against the other three
size by size
| Saily | GigSky | Airalo | Yesim | |
|---|---|---|---|---|
| 1GB | $3.99 / 7d | $2.99 / 7d | $4.00 / 3d | $4.44 / 30d |
| 5GB / 30 days | $10.99 | $10.29 | $11.00 | $10.56 |
| 10GB / 30 days | $17.99 | $16.79 | $18.00 | $19.20 |
| 20GB / 30 days | $24.99 | none | $25.00 | $29.76 |
| Unlimited, 7 days | $26.99 | $24.49 | $26.50 | from $4.20/day |
| Unlimited, 30 days | $71.99 | $65.99 | $69.00 | from $4.20/day |
| Daily cap | 5GB/day, 1 Mbps after | 3.5GB/day, then slowed (speed not published) | 3GB/day, 1 Mbps after | not published |
| Japanese network | KDDI + SoftBank | Docomo + SoftBank | KDDI + SoftBank | KDDI; Docomo on some plans |
| Trustpilot | 4.7 · 32,870 | 4.3 · 8,403 | 4.2 · 48,959 | 4.3 · 2,996 |
Saily is never the cheapest and never far off. It wins 20GB over a full month by a cent, it wins the daily cap by a wide margin, and it wins the trust column outright. It loses the one column this site cares most about: its networks are KDDI and SoftBank, with no Docomo.
Buying and activating Saily
four minutes
- Buy on the Saily website at home on wifi, and check the currency selector shows USD before comparing against the tables here.
- Pick the length honestly. Saily's unlimited ladder has seven rungs, so buy ten days for a nine-day trip rather than fifteen. Nobody else in this comparison lets you do that.
- Install the profile before you fly. It does not start counting until it connects in Japan.
- On landing: Saily line on for data, home line on for calls with data roaming off. If it will not attach, set network selection to manual and pick KDDI (au) or SoftBank, the two networks Saily names. Full setup and fixes.
Buy Saily if, skip it if
the short version
Buy it if
- You are hotspotting a laptop. The 5GB daily cap is the largest published in Japan, and Saily's Japan page allows hotspot with no separate limit stated.
- You want 20GB over a full thirty days, at $24.99.
- Your trip length is awkward. Seven unlimited lengths means you are not paying for days you will not use.
- Support matters to you. The 4.7 from 32,870 reviews is the best record on this site.
Skip it if
- Your route leaves the cities. Saily rides KDDI and SoftBank, not Docomo, and in the Alps or Hokkaido that is not a detail. Take GigSky on Docomo.
- You rely on services that geolocate by exit address. Reviewers report Saily's Japan traffic exiting via Hong Kong.
- You want the cheapest 10GB. GigSky is $1.20 less.
- You want the cheapest week of unlimited. GigSky's is $24.49 against Saily's $26.99, with 3.5GB a day instead of 5GB, on Docomo.
Saily Japan questions
short answers
Which network does Saily use in Japan?
KDDI and SoftBank, named on Saily's own Japan page, checked 2026. That is the same pair as Airalo and leaves out NTT Docomo, the network with the deepest rural coverage. If you need Docomo, GigSky publishes NTT Docomo and SoftBank.
Is Saily unlimited really unlimited in Japan?
No, and Saily says so: 5GB per day at full speed, then up to 1 Mbps until the allowance resets at midnight local time. That is the largest published daily allowance among the brands we link, larger than Airalo's 3GB, GigSky's 3.5GB and Nomad's 2GB.
Is Saily better than Airalo for Japan?
For hotspotting and long stays, yes: a bigger daily cap, a better trust score and a cheaper 20GB over thirty days. For a city trip, Airalo is a dollar cheaper at 20GB over fifteen days. Both ride KDDI and SoftBank, both print 1 Mbps after the cap, and neither has NTT Docomo.
How much is Saily unlimited for Japan?
From $18.99 for five days up to $71.99 for thirty, checked 2026, in seven lengths: 5, 7, 10, 15, 20, 25 and 30 days, a week at $26.99. All carry the same 5GB per day cap. At thirty days that is 48 cents per full-speed gigabyte if you use every day of it, which is the cheapest full-speed data in this comparison.
Is Saily trustworthy?
It has the best record of any brand on this site: Trustpilot 4.7 across 32,870 reviews as of 2026, 83 per cent five-star, replies to 99 per cent of negative reviews. It is run by Nord Security, the NordVPN company. The one substantive complaint we found is about Japan traffic exiting through Hong Kong, which is a routing quirk rather than a support failure.
5GB a day, published, the largest in Japan
Seven unlimited lengths from five days to thirty, a 20GB bucket at $24.99 over a full month, and the best support record on this site at 4.7 from 32,870 reviews. If your route leaves the cities, read the network section above first.
See Saily Japan plansSources & freshness: Every Saily price, the "5GB/Day without a speed limit" cap, "Unlimited data at up to 1 Mbps" after it, hotspot terms and the networks ("including KDDI and SoftBank") from Saily's own Japan page (saily.com/esim-japan/), in USD, checked 2026, before promo codes. Midnight reset from Saily's Terms of Service (saily.com/legal/terms-of-service/) and help centre. Rival prices re-checked on each brand's own page in 2026. The Hong Kong exit-address reports come from traveler reviews on esimdb and are traveler reports, not a tested finding. Trustpilot 4.7 across 32,870 reviews, checked 2026. How we test.