Eight plans · one with no cap · one brand that will not say
Unlimited eSIM for Japan
Almost every unlimited plan sold for Japan is an allowance with a throttle behind it. This page puts all of them in one table, in hours of video rather than gigabytes.
Every Japan unlimited cap in one table
published numbers only
| "Unlimited" plan | Real daily high-speed cap | After the cap |
|---|---|---|
| Sim Local KDDI (au) Unlimited · $13.00 (4 days) to $77.50 (31 days) · unlinked | no daily cap | Sold by Sim Local as an official KDDI (au) local eSIM, and the only plan here sold with no daily cap. Hotspot is limited: 3GB on 4 days, 6GB on 7, 15GB on 15, 30GB on 31. We earn nothing from it. |
| Mobal 5G Unlimited · ¥1,650 (3 days) to ¥12,300 (31 days) · unlinked | none printed | A Japanese provider on KDDI, priced in yen only (7 days is ¥3,850, about $26 at ¥150). Mobal prints a hotspot allowance, 15GB on its 16-day plan, and no daily speed cap. Data only. |
| Saily Unlimited · $18.99 (5 days) to $71.99 (30 days) | 5GB/day | The largest daily allowance among the brands we link. Then "unlimited data at up to 1 Mbps" until the allowance resets at midnight local time, per Saily's own Japan page and Terms. Seven lengths, a week at $26.99. Hotspot allowed. On KDDI and SoftBank, named by Saily. |
| Ubigi Unlimited · $25 (8 days), $39 (15 days), $65 (30 days) · unlinked | 5GB/day or a total | The 8-day plan gives 5GB a day; the 15- and 30-day plans give 30GB and 60GB at full speed in total. After that, 2 Mbps, the fastest fallback here. Docomo, KDDI and SoftBank on one profile. The full Ubigi review is here. |
| GigSky Unlimited · $3.49 (1 day) to $65.99 (30 days) | 3.5GB/day | Then slowed, speed not published by GigSky. High-speed data resumes every 24 hours from plan activation. Sold for any length from 1 to 30 days: 5 days $18.49, 7 $24.49, 10 $32.49, 15 $44.99, 20 $54.49, list prices on GigSky's Japan page. On NTT Docomo and SoftBank. |
| Airalo Moshi Moshi Unlimited · $11.50 (3 days) to $69.00 (30 days) | 3GB/day | Then 1 Mbps for the rest of the day. One megabit still carries maps, LINE, transit apps and voice calls; it does not carry video or a laptop hotspot. |
| Nomad Unlimited · $11 (3 days) to $49 (21 days) · unlinked | 2GB/day | Then 1 Mbps. The smallest cap on this table. Two gigabytes is roughly an hour of high-definition video, so this is a maps-and-messaging plan with an unlimited label on it. |
| Yesim Unlimited · from $4.20 a day | none published | Yesim links a fair usage policy and never gives the number. The only plan here where you cannot know what you bought before you buy it. |
Figures from each brand's own plan pages, checked 2026. When the day resets depends on the brand: GigSky counts 24 hours from activation; Saily resets at midnight local time; others say only "per day". Mobal prices are in yen; Sim Local, Ubigi, GigSky, Airalo and Nomad in USD.
If you are buying unlimited from a brand we link, buy the largest number anyone will print. Saily's 5GB a day is 67 per cent more full-speed data than Airalo's 3GB.
See Saily unlimited Read the Saily reviewWhat each daily cap is in hours
gigabytes are not a unit anyone thinks in
"5GB a day" means nothing until you know what you would spend it on. Rough figures, at the quality settings phones default to on cellular:
| Daily cap | HD video | Video calls | Maps, LINE, photos |
|---|---|---|---|
| 5GB · Saily | ≈4–5 hours | ≈8 hours | a whole day of anything, plus a film |
| 3.5GB · GigSky | ≈3 hours | ≈6 hours | a whole day of anything, plus a couple of episodes |
| 3GB · Airalo | ≈2.5 hours | ≈5 hours | a whole day of anything, comfortably |
| 2GB · Nomad | ≈1.5 hours | ≈3 hours | a whole day of anything, just about |
Approximate, and generous to the caps rather than to us: video at roughly 1GB an hour for 720p and more at 1080p, video calls at about 600MB an hour, sightseeing use at 400 to 700MB a day. Your numbers will differ.
Read that table honestly and the conclusion is uncomfortable for the whole product category. Every one of these caps covers a normal sightseeing day with room to spare. If you are not streaming video or tethering a laptop, you are not going to reach 2GB, let alone 5GB, and you are paying two to three times the price of a fixed bucket for a ceiling you will never touch.
Price per day, and price per gigabyte you will actually use
the real comparison
| Plan | Total | Per day | Per GB if you max the cap |
|---|---|---|---|
| Saily unlimited, 7 days | $26.99 | $3.86 | $0.77 |
| Saily unlimited, 30 days | $71.99 | $2.40 | $0.48 |
| Airalo unlimited, 5 days | $17.00 | $3.40 | $1.13 |
| Airalo unlimited, 30 days | $69.00 | $2.30 | $0.77 |
| GigSky unlimited, 7 days | $24.49 | $3.50 | $1.00 |
| GigSky unlimited, 30 days | $65.99 | $2.20 | $0.63 |
| Ubigi unlimited, 15 days · unlinked | $39.00 | $2.60 | $1.30 (30GB total) |
| Sim Local KDDI unlimited, 7 days · unlinked | $19.00 | $2.71 | no cap |
Two things fall out of that table. Saily at thirty days is the cheapest full-speed gigabyte in Japan, at 48 cents, if and only if you genuinely use five gigabytes every single day. And Ubigi's fifteen days at $39.00 undercuts Saily's $48.99 and Airalo's $48.00 for the same window, with 30GB at full speed and no commission for us. For a week, Sim Local's KDDI plan at $19.00 with no daily cap is the cheapest unlimited we found, also unlinked.
When a fixed bucket beats every unlimited plan
which is most of the time
Put plainly: unless you are streaming video daily, tethering a laptop for work, or uploading photo and video files every night, a fixed plan is cheaper and there is nothing to think about. The data calculator works out which size you need.
The cases where unlimited genuinely wins:
Remote work. A tethered laptop with video calls runs 2 to 3GB a day on its own. Over two weeks that is 30 to 40GB, which no fixed plan we can link even sells. Saily's fifteen-day unlimited at $48.99 is the answer.
Short and heavy. A five-day trip where you will stream on the Shinkansen every day. Airalo's five days at $17.00 with 3GB a day is $3.40 a day for a ceiling you will actually reach.
Not wanting to think about it. A legitimate reason. If checking a data balance would put a small grey cloud over your holiday, paying $25 extra to never do it is a rational purchase and we are not going to talk you out of it.
Which unlimited plan to buy
if you have decided you want one
Saily
The largest published cap in Japan $26.99 unlimited, 7 days, 5GB/day- 5GB a day at full speed, 67 per cent more than Airalo and the biggest daily number among the brands we link
- Seven lengths from five days to thirty, so a nine-day trip does not have to buy fifteen
- Trustpilot 4.7 from 32,870 reviews, the best record on this site
Watch out: It rides KDDI and SoftBank, not Docomo, and a week costs $2.50 more than GigSky's smaller 3.5GB cap.
Trustpilot 4.7/5 · 32,870 reviews
See Saily unlimited plansAiralo
Both numbers printed, cheapest short unlimited we link $17.00 unlimited, 5 days, 3GB/day- 3GB a day, then 1 Mbps, both published, so you can plan around the ceiling instead of discovering it
- Cheapest short unlimited we link: three days for $11.50 and five for $17.00
- On KDDI and SoftBank, both published, both strong along the corridor
Watch out: The 3GB cap is three fifths of Saily’s, and there is no NTT Docomo.
Trustpilot 4.2/5 · 48,959 reviews
See Airalo unlimited plansGigSky
Unlimited on Docomo, cheapest linked week $24.49 unlimited, 7 days, 3.5GB/day- 3.5GB a day at full speed, printed on GigSky's own Japan page, resetting 24 hours from activation
- Lists NTT Docomo on every Japan plan
- Any length from 1 to 30 days, a week for $24.49, and a free 100MB first so you can test the network
Watch out: GigSky does not say how slow it gets after 3.5GB, and fifteen days at $44.99 is not cheap.
Trustpilot 4.3/5 · 8,403 reviews
See GigSky unlimitedAnd the ones we cannot sell you: Ubigi's fifteen days at $39.00 is cheaper than Saily and Airalo for the same window, on Docomo, KDDI and SoftBank, with 30GB at full speed then 2 Mbps. Sim Local's KDDI (au) plan, $19.00 for a week with no daily cap, is the closest thing to truly unlimited we found. We earn nothing from either.
Unlimited Japan eSIM questions
short answers
Is there a truly unlimited eSIM for Japan?
One that we found: Sim Local's KDDI (au) plan, sold with no daily cap, $19.00 for 7 days, hotspot limited to 6GB. Every other plan is an allowance: Saily 5GB a day, GigSky 3.5GB, Airalo 3GB, Nomad 2GB; Yesim publishes no figure. Checked 2026.
Which unlimited eSIM has the biggest cap in Japan?
Among brands we link, Saily, at 5GB per day at full speed. Ubigi's 8-day plan matches it, and Sim Local's KDDI plan has no daily cap at all. Saily's allowance is roughly four to five hours of high-definition video or a full working day of a tethered laptop. Prices run from $18.99 for five days to $71.99 for thirty.
Is unlimited data worth it for Japan?
Only if you use more than about 670MB a day over a month, or 1.4GB a day over two weeks. A normal sightseeing day of maps, messaging, translation and photos is 400 to 700MB, so most visitors are better off with a 20GB fixed plan at $24.99. Unlimited earns its price for remote work, daily streaming and heavy hotspot use.
What happens when you hit the daily cap?
Your speed drops until the allowance resets. The reduced speeds brands publish: Ubigi 2 Mbps, Airalo and Nomad 1 Mbps, Saily about 1 Mbps until midnight local time. GigSky says only that it slows, with high speed back 24 hours from activation; Yesim says nothing. Checked 2026.
Does unlimited data include hotspot in Japan?
GigSky states hotspot is included with unlimited use, and Saily allows it with no separate limit stated, so the daily cap is shared between the phone and anything tethered to it. The local KDDI plans cap hotspot separately: Sim Local 6GB a week, Mobal 15GB on its 16-day plan. That matters: a laptop on a video call can spend a 3GB daily allowance in an afternoon. If you plan to tether daily, take the 5GB cap rather than the 3GB one.
5GB a day, in writing
The largest published daily allowance among the brands we link, in seven lengths from five days to thirty. If you are not going to use more than about 1.4GB a day, buy the 20GB bucket at $24.99 instead and keep the difference.
See Saily unlimited plansSources & freshness: Caps and prices from each brand's own Japan plan pages, checked 2026, before promo codes: Airalo, GigSky, Ubigi, Nomad, Sim Local and Yesim in USD; Mobal in JPY. Saily's seven lengths, cap, 1 Mbps fallback and networks from Saily's own Japan page, checked 2026; its midnight reset from Saily's Terms. GigSky list prices (a temporary discount of about 25% was running), 3.5GB cap and 24-hour reset from GigSky's own Japan page, checked 2026; GigSky does not publish the reduced speed. Where a brand publishes no figure this page says so rather than estimating one. We have not run our own throttle or speed tests. How we test.