Best eSIM for Japan 2026: Top Providers Compared

Japan is the single most bought travel eSIM destination, and it is also one of the trickiest to shop for. Ask which provider is cheapest and the honest answer is a question back: how long are you going, and how much data do you actually want? Change either one and the winner changes. We priced every provider listed for Japan on RoamPrice on 24 August 2026, applied the discount codes that work, and came out with four different winners across four ways of buying.

The discount codes, first

These change the ranking, so apply them before you compare anything. Every price in this guide already includes them.

10–15%

Three codes, plus one automatic cashback Tap a code to copy it, then paste it at that provider's checkout. Qoolline needs nothing entered.

ROAMPRICECopy Ubigi — 10% off

ROAMPRICECopy Saily — 10% off

ROAMPRICE15Copy Nomad — 15% off

QoolCash 10% back Qoolline — automatic, no code needed

One difference worth understanding: the three codes come off the price at checkout, so you pay less immediately. Qoolline's QoolCash is not a code at all — it is a built-in feature of the platform that credits 10% of every purchase back to your Qoolline account, automatically. You still pay the full price on the day; the value comes back as balance you can spend on your next plan. The tables show its effective cost after that credit so the comparison is like for like.

Angle 1 — the 10GB benchmark

Ten gigabytes is what a normal one- to two-week trip needs if you download offline maps before you fly: navigation, messaging, a few uploads, some browsing on trains. It is also the size where providers price most aggressively, which makes it the fairest single comparison.

Provider	Plan	List	Code	You pay	$/GB
	10GB · 7 days	$14.00	ROAMPRICE−10%	$12.60 $14.00	$1.26	Get plan →
	10GB · 30 days	$16.19	ROAMPRICE−10% · already in price	$16.19	$1.62	Get plan →
	10GB · 7 days	$17.00	no code	$17.00	$1.70	Get plan →
	20GB · 30 days	$23.00	ROAMPRICE15−15%	$19.55 $23.00	$0.98	Get plan →
	5GB · 30 days	$13.45	QoolCash10% back, automatic	$12.11 $13.45	$2.42	Get plan →
	50GB · 30 days	$45.95	no code	$45.95	$0.92	Get plan →

Cheapest plan in the 10GB band with validity of at least seven days, from Japan listings on RoamPrice, 24 August 2026, USD.

Ubigi takes it at $12.60 — but read the validity column before you buy. That plan runs seven days, not thirty, which is fine for a one-week trip and useless for a fortnight. Its 30-day 10GB plan costs $14.85 with the code, still the cheapest month-long option on the page. Saily is second at $16.19 with a full 30 days and the discount already baked into the listed price. Airalo's cheapest 10GB is a seven-day plan at $17.00 with no code available.

Angle 2 — small plans for short trips

Four days in Tokyo, or a traveler who lives on hotel wifi and just wants maps and messaging on the move.

Provider	Plan	List	Code	You pay	$/GB
	5GB · 15 days	$10.00	ROAMPRICE−10%	$9.00 $10.00	$1.80	Get plan →
	5GB · 30 days	$9.89	ROAMPRICE−10% · already in price	$9.89	$1.98	Get plan →
	5GB · 7 days	$10.00	no code	$10.00	$2.00	Get plan →
	20GB · 30 days	$23.00	ROAMPRICE15−15%	$19.55 $23.00	$0.98	Get plan →
	5GB · 30 days	$13.45	QoolCash10% back, automatic	$12.11 $13.45	$2.42	Get plan →
	50GB · 30 days	$45.95	no code	$45.95	$0.92	Get plan →

Best value plan between 1GB and 5GB with validity of at least seven days. Qoolline's figure is after its automatic 10% QoolCash credit.

At this size the gaps are small in absolute terms — a couple of dollars across the whole field — so validity matters more than price. Saily's 5GB runs a full 30 days for $9.89. Ubigi's is $9.00 but expires after 15. Airalo's is $10.00 for 7 days. If your trip is a long weekend, take the cheapest; if it is anything longer, take the one that outlasts it.

Qoolline has the lowest sticker in Japan at any size — $3.45 for 1GB, $3.11 after cashback — which makes it the pick if you genuinely need almost nothing.

Angle 3 — big data, long stays and tethering

A month in Japan, a working trip with a laptop attached, or two people sharing one connection. This is where the field separates hardest.

Provider	Plan	List	Code	You pay	$/GB
	50GB · 30 days	$55.00	ROAMPRICE−10%	$49.50 $55.00	$0.99	Get plan →
	20GB · 30 days	$22.49	ROAMPRICE−10% · already in price	$22.49	$1.12	Get plan →
	20GB · 15 days	$24.00	no code	$24.00	$1.20	Get plan →
	50GB · 30 days	$35.00	ROAMPRICE15−15%	$29.75 $35.00	$0.59	Get plan →
	5GB · 30 days	$13.45	QoolCash10% back, automatic	$12.11 $13.45	$2.42	Get plan →
	50GB · 30 days	$45.95	no code	$45.95	$0.92	Get plan →

Best value plan of 20GB or more with validity of at least seven days.

Nomad wins this outright. Fifty gigabytes for $29.75 with ROAMPRICE15 is $0.60 per gigabyte — roughly half of what anyone else charges at any size in Japan, and cheaper in absolute terms than several providers' 20GB plans. Roamless offers the same 50GB for $45.95 and Ubigi for $49.50.

If 50GB is more than you need, Saily's 20GB at $22.49 is the value pick, and Airalo's 20GB at $24.00 runs only 15 days.

Angle 4 — unlimited, by how long you are staying

Unlimited plans are priced per day rather than per gigabyte, so the ranking rearranges completely depending on trip length. This table is the clearest illustration in the whole comparison: four trip lengths, four different cheapest providers.

Cheapest unlimited plan covering each trip length, with codes applied. The small figure is the plan's actual validity — sometimes you buy a longer plan because it is cheaper than the exact-fit one. Highlighted cell is the cheapest for that row.

Read down the highlighted column. Nomad is cheapest for a three-day city break at $9.35 and for a full week at $21.25. Saily takes the ten-day slot at $31.49. Ubigi owns everything from two weeks up, and the gap at a month is enormous — $40.50 against $64.79 and $69.00. Airalo is competitive at five days.

Also worth knowing: "unlimited" is never literally unlimited. Every provider here applies a daily fair-use threshold, after which speeds drop for the rest of the day. If you plan to tether a laptop all day, a large fixed bundle usually behaves better than an unlimited plan.

So which one should you buy?

One week, normal use

Ubigi 10GB

$12.60 with ROAMPRICE for the 7-day plan, $14.85 for the 30-day one. Cheapest 10GB either way.

Two weeks, no maths

Saily 10GB

$16.19 with the code already applied, a clean 30 days, no validity trap to fall into.

Month, laptop, or sharing

Nomad 50GB

$29.75 with ROAMPRICE15. At $0.60 per gigabyte nothing else in Japan is close.

Unlimited for a month

Ubigi Unlimited

$40.50 with ROAMPRICE, against $64.79 and $69.00 from the next two.

What you will actually be doing with that data

Three trips that eat data at very different rates — useful for sizing your plan before you buy.

Two things that catch people out in Japan

Validity is not always what the listing says. Several Japan plans are sold in short-window versions alongside the 30-day one — a 10GB plan that runs seven days sits right next to a 10GB plan that runs thirty, a couple of dollars cheaper. Sorting by price puts the short one on top. Always read the validity next to the price, especially at the 10GB tier.

Coverage is excellent everywhere, so buy on price and plan shape. Japan's networks reach into subway tunnels, mountain valleys and the length of the shinkansen line. Every provider here resells capacity on those same national networks, so the differences that matter are price, validity and how much data you get — not signal.