eSIM for Japan: 5 that work the moment you land

A Japan tourist eSIM installs before you fly and connects on landing
Ubigi reaches Docomo and au; Saily and Holafly use KDDI and SoftBank
Only Mobal gives you a Japanese phone number with SMS

The five

Best for	Where to get it	Score	7 days, about 10 GB
Two networks — Docomo and au — and it starts itself — if you can’t decide	Ubigi Get it	85/100	¥2,210 (seven days, 10 GB)
KDDI’s own tourist eSIM, and the cheapest 10 GB week here	povo2.0 Japan SIM Get it	83/100	¥1,430 (seven days, 10 GB)
The most generous unlimited — 5 GB a day — and tethering without limits	Saily Get it	78/100	¥2,840 (thirty days, 10 GB)
The only one that can give you a Japanese phone number	Mobal Get it	69/100	¥3,850 (eight days, 10 GB)
Every plan unlimited — you only choose the days	Holafly Get it	66/100	¥4,342 (seven days, unlimited)

These are Japanese services. Where a plan needs a Japanese address, a bank account or a residence card, we say so on the row itself.

Two networks — Docomo and au — and it starts itself

Ubigi

Run by Transatel, part of the NTT group
Cheap by this list’s standards: 10 GB for seven days

See plans and prices→

Why it made the five

Reaches both Docomo and au networks
Starts automatically the moment it connects in Japan
Tethering allowed — the site says data sharing is permitted
Bought and topped up in the app
Right for: Anyone who wants Docomo coverage as well, and nothing to do on landing.
Not for: Anyone who needs a Japanese phone number, or wants to watch video without counting.
Worth knowing: Priced in dollars, so what you pay depends on the rate and your card’s foreign fee. Start using it within six months of purchase or it expires.

Score breakdown — 85/100

Criterion	Stars	Why
Quality	★★★★★	Two networks — KDDI and NTT Docomo — and 4G/5G stated: two points
Value for money	★★★★☆	14 dollars for 7 days and 10 GB, about ¥2,210
Easy to live with	★★★★☆	App purchase and top-up, and tethering allowed; no Japanese number
Trust	★★★★☆	Transatel, in the NTT group since 2019. 4.6 from 10,536 US App Store ratings
Only here	★★★★☆	The only global eSIM app here that reaches Docomo — the others sit on au and SoftBank

KDDI’s own tourist eSIM, and the cheapest 10 GB week here

povo2.0 Japan SIM

Data-only eSIM for visitors, sold by KDDI itself
Buy and install before you fly; it works on arrival
If you run out you can add more

See plans and prices→

Why it made the five

Direct from KDDI, one of Japan’s three major carriers, on the au network
Data bundles plus unlimited top-ups from a couple of hours up to seven days
No identity documents needed for the data-only eSIM
Site in English, Korean, Vietnamese and simplified Chinese
Right for: Getting onto a Japanese carrier’s own network for as little as possible.
Not for: Anyone who needs to tether a laptop, or who needs a Japanese number.
Worth knowing: Data only — no phone number. We could not confirm on the official pages whether tethering is permitted, so check before you buy.

Score breakdown — 83/100

Criterion	Stars	Why
Quality	★★★★☆	au’s 5G network is stated, but it is a single network
Value for money	★★★★★	¥1,430 for 7 days and 10 GB — the cheapest here
Easy to live with	★★★☆☆	Top-ups bought in the povo2.0 app; tethering unconfirmed; no Japanese number
Trust	★★★★★	KDDI and Okinawa Cellular. The app rates 4.8 from 58,050 ratings on the Japanese App Store
Only here	★★★★☆	A tourist eSIM sold by a major Japanese carrier itself, with unlimited data by the hour — 2, 6 or 24 hours — which nobody else here offers

The most generous unlimited — 5 GB a day — and tethering without limits

Saily

Run by the company behind NordVPN
Uses KDDI and SoftBank in Japan
Suits a laptop or someone else’s phone sharing the connection

See plans and prices→

Why it made the five

Unlimited runs at full speed to 5 GB a day; data plans from 1 GB to 20 GB
Tethering allowed on every plan, with no stated cap
Live chat around the clock
Ad-blocking and other security features built into the app
Right for: Sharing the connection with other devices, or wanting unlimited that stays fast.
Not for: A short trip with light use — there is no 7-day 10 GB plan, so you buy 30 days.
Worth knowing: Priced in dollars. Start using it within 180 days of purchase.

Score breakdown — 78/100

Criterion	Stars	Why
Quality	★★★★★	KDDI and SoftBank, with 4G/LTE and 5G stated: two points. Unlimited runs full speed to 5 GB a day, then 1 Mbps
Value for money	★★★☆☆	No 7-day 10 GB plan; 30 days and 10 GB is 17.99 dollars, about ¥2,840
Easy to live with	★★★★☆	App purchase and top-up, and uncapped tethering; no Japanese number, though a US number can be added
Trust	★★★★☆	Nordvpn S.A. 4.7 from 12,638 US App Store ratings
Only here	★★★☆☆	5 GB a day at full speed on unlimited, against Nomad’s 2 GB and Airalo’s 3 GB

The only one that can give you a Japanese phone number

Mobal

A telecoms company serving English-speaking travellers for decades
Data-only eSIM runs on Docomo
The numbered eSIM covers restaurant bookings by phone and verification codes

See plans and prices→

Why it made the five

A data-only eSIM, and one with a Japanese number (070/080/090) and SMS
English-language support; the data eSIM arrives by email in minutes
Unlimited plans allow tethering up to 15 GB over a 16-day period
Trading since 1989, with more than 250,000 travellers served
Right for: Anyone who needs a Japanese number, or who wants to be able to ask someone in English.
Not for: Anyone optimising for price.
Worth knowing: The numbered eSIM requires identity verification, so it cannot be emailed — the access code is posted, or collected in Japan. It is a monthly contract, so you must cancel after your trip.

Score breakdown — 69/100

Criterion	Stars	Why
Quality	★★★★☆	5G stated; the data eSIM is on Docomo, unlimited on KDDI. After 10 GB the speed falls to 200 kbps
Value for money	★★☆☆☆	No 7-day 10 GB plan; 8 days and 10 GB is ¥3,850
Easy to live with	★★★★☆	Tethering on unlimited plans, and a Japanese number available; email delivery timed to your arrival; English support; no app
Trust	★★★☆☆	No App Store app. Trading since 1989 with over 250,000 travellers, per its own site
Only here	★★★★★	The only provider here offering travellers a Japanese phone number with SMS, which restaurant bookings and verification codes need

Every plan unlimited — you only choose the days

Holafly

Choose by trip length only: no data tiers
Removes the arithmetic if you upload photos and video or use maps all day
The most expensive option here

See plans and prices→

Why it made the five

Every Japan plan is unlimited data — you pick the number of days
Tethering allowed up to 1 GB a day
Bought and managed in the app
4.8 from 38,208 US App Store ratings
Right for: Heavy use — video, uploads, maps all day — without watching a counter.
Not for: Light use. If you only need maps and messages, a data bundle is far cheaper.
Worth knowing: Priced in dollars. Tethering is limited to 1 GB a day.

Score breakdown — 66/100

Criterion	Stars	Why
Quality	★★★★☆	KDDI and SoftBank, so one point; 5G is not stated. Speeds may be managed for up to a day when the network is busy
Value for money	★☆☆☆☆	No 10 GB bundle; 7 days unlimited is 27.50 dollars, about ¥4,342
Easy to live with	★★★★☆	App purchase and management, tethering to 1 GB a day; no Japanese number
Trust	★★★★★	4.8 from 38,208 US App Store ratings; Trustpilot 4.5 from 112,066 reviews per its own site
Only here	★★★☆☆	Japan plans are unlimited only, so there is no capacity to choose — unusual clarity, if you can use it

Know before you buy

All of these use one of Japan’s three big networks — NTT Docomo, au (KDDI) or SoftBank. Coverage differences between them matter mostly in the mountains and on small islands.
‘Unlimited’ is never unlimited: Nomad gives 2 GB a day at full speed then 1 Mbps, Saily 5 GB, and Holafly reserves the right to slow you for up to a day when the network is busy.
Tethering is not a given. Nomad, Ubigi and Saily allow it; Holafly caps it at 1 GB a day; Mobal’s 16-day unlimited caps it at 15 GB for the whole trip.
Almost all travel eSIMs are data only. If you need a Japanese number to book a restaurant or receive an SMS code, that narrows the field to one.
Your phone must not be network-locked. Check with your carrier at home before you buy anything.
Prices quoted in dollars move with the exchange rate and your card issuer’s fee; we converted at ¥157.89 to the dollar on 18 September 2026.

How we chose: theme, conditions, scoring

How we chose

Candidates: 11
Met every condition below: 8
Kept: five, each the best at something different

Conditions (all of them, not most of them)

Works in Japan, on one of the major Japanese networks
Has a plan of 5 GB or more for seven days, or unlimited (a 30-day 10 GB plan counts where no 7-day one exists)
Sold as an eSIM
You can buy it in English and install it before you arrive in Japan
On sale to individuals as of September 2026

Scoring

Five criteria, one to five stars each, weighted to one hundred points. Every star says where the number came from.

Quality25 pts
- Starts at three stars, since all of them use a major Japanese network. Add one for reaching two or more networks, and one if the provider states 5G support. Any daily cap on an unlimited plan is written into the reason.
Value for money25 pts
- The cheapest plan giving about 10 GB for seven days, converted to yen. Under ¥1,500 is five stars, under ¥2,500 four, under ¥3,000 three, under ¥4,000 two, above that one. Where no 7-day 10 GB plan exists we use the nearest equivalent and say so.
Easy to live with25 pts
- Starts at two stars, since all of them sell in English and install before arrival. Add one for buying and topping up in an app, one if tethering is stated as allowed, and one if a Japanese phone number is available.
Trust15 pts
- App Store ratings: 4.5 or better with 30,000+ ratings is five stars, 4.5 with 10,000+ four, otherwise three. The operating company is named in the reason.
Only here10 pts
- How far the thing it does cannot be had from anyone else on the same terms. Our judgement, with the reason stated.

What we dropped

Candidate	Verdict	Why
Nomad	Runner-up (76/100)	The score is high enough, but its character overlaps with the five
Airalo	Runner-up (69/100)	The score is high enough, but its character overlaps with the five
Sakura Mobile	Runner-up	Unlimited on au with 6 GB of tethering over seven days, a 3 GB-a-day Docomo plan, and good English support — but the seven-day price is not shown until you select dates, so we could not record a tax-inclusive figure to score.
IIJmio Japan Travel SIM	Outside the theme	Sold through terminals in Lawson and Ministop stores at prices set by the retailer, so you cannot buy and install it before arriving.
Rakuten Communications mobile data service	Outside the theme	A visitor eSIM on the Rakuten network, but sold through hotels and convenience stores as a business service — individuals cannot apply directly.
NTT Docomo Japan Welcome SIM	Outside the theme	A visitor prepaid SIM from 2017; we could not confirm on Docomo’s site that it is still sold to individuals as of September 2026.

Questions visitors ask

What do I need to do before I fly?

Buy the eSIM and install it on your phone. Ubigi starts itself the moment it finds a network in Japan; Mobal’s data eSIM arrives by email and can be set up for your arrival date. The one thing that will stop you is a network-locked phone, so check with your carrier at home first.

Do I need a Japanese phone number?

Usually not. Most of these are data only, and if you call through LINE or WhatsApp that is enough. You need a real number for telephone restaurant bookings and for the SMS codes some Japanese services send. Mobal is the only provider here that sells one to travellers — and because it needs identity verification, it cannot be emailed to you.

Is ‘unlimited’ really unlimited?

No, and the providers say so. Nomad runs full speed to 2 GB a day then caps at 1 Mbps; Saily to 5 GB a day then 1 Mbps; Holafly states it may manage your speed for up to a day when the network is congested. If you want unlimited that stays fast, Saily’s daily allowance is the largest we could verify.

Can I share the connection with a laptop or someone else’s phone?

Nomad, Ubigi and Saily all state that tethering is allowed, Saily with no cap. Holafly limits it to 1 GB a day, and Mobal’s 16-day unlimited to 15 GB over the whole period. We could not confirm povo’s position, so ask before buying if this matters.

Can someone in Japan buy one for a visiting relative?

Yes. All of these are bought online, with the eSIM delivered by email or in an app, so you can forward the QR code and instructions for the traveller to scan on their own phone. Where the service is managed through an app, it is simpler if the traveller installs the app themselves, so they can top up.

eSIM or pocket Wi-Fi?

An eSIM is lighter, cheaper and needs no collection or return. Pocket Wi-Fi makes sense when several people are travelling together, when a phone is too old to take an eSIM, or when you need a device that can be handed around. We have a separate guide to short-term Wi-Fi rental.

Changes

2026-10-25　First published. Scored from 11 candidates.