Japan: local SIM, or eSIM, and which network you land on

The decision is about coverage, not cost

Japan is one of the few countries where local SIMs and travel eSIMs land in roughly the same price band. A tourist SIM bought at a Japanese airport is about $12; eSIM plans start at $3.99. Nobody is being robbed on either side.

What actually separates the options is which of the four national networks you end up on, and that depends entirely on where you are going.

Buying locally: counters and vending machines

The national carriers are NTT Docomo, SoftBank, au by KDDI and Rakuten Mobile. Tourist SIMs are sold at Narita (NRT), Haneda (HND), Kansai (KIX), Chubu (NGO), Fukuoka (FUK) and Sapporo (CTS), through both staffed counters and 24-hour vending machines. The vending machines matter: a red-eye arrival at Haneda at 01:00 still gets you connected.

Two constraints. A passport is required for registration, and the SIMs are data-only — no Japanese number, no calls, no SMS. Everyone uses LINE and WhatsApp over data anyway, so this is less of a limitation than it sounds, but it does mean you cannot use a local number for restaurant bookings.

The eSIM options

Cheapest entry plan from each provider we track, from our Japan data — Airalo and Saily checked 13 August 2026, Nomad 17 August 2026, Holafly 18 August 2026:

Provider	Cheapest plan	Price	Network	Status
Saily	1 GB / 7 days	$3.99	not disclosed	verified
Airalo	1 GB / 3 days	$4	not disclosed	verified
Nomad	1 GB / 7 days	$4	not disclosed	verified
eSIM Go	3 GB / 30 days	$8.50	None — the SoftBank entry was our own text	not on sale
Holafly	Unlimited / 3 days	$11.90	not published	verified

Notice the network column, and notice what has left it. This table used to show Holafly on Docomo and SoftBank, and a one-day Holafly plan at $3.99. Neither survived contact with Holafly's own site: we read its Japanese prices there on 18 August 2026 and found six durations starting at three days for $11.90, and no host carrier named for Japan or for any other country. Both the $3.99 day and the Docomo listing came from our own data. That leaves nobody publishing a Japanese network at all. eSIM Go appeared to, listing SoftBank, but that entry came from this site's own generated text — it sells wholesale to resellers and has no consumer page on which it could name a carrier, nor any price a traveller can pay. Airalo, Saily, Nomad and Holafly do not publish which Japanese carrier sits behind their plans — eSIMCard is the single exception, naming KDDI, NTT Docomo and SoftBank on its own Japan page; an earlier version of this page credited Nomad with SoftBank and KDDI, which Nomad does not publish anywhere, and Airalo sells its Japanese plan under its own product name, Moshi Moshi, which is a product label rather than a network.

Why Docomo keeps coming up

Docomo has the widest rural, mountain and island coverage in Japan. SoftBank and KDDI both run excellent networks — coverage in the 97% range, strong urban speeds, SoftBank leading on median urban speed — and for the Tokyo–Kyoto–Osaka corridor the difference between them and Docomo is academic.

It stops being academic here: hiking trails in the Japanese Alps above 1,500 m, the remote Hokkaido interior, some smaller Okinawa islands, and mountain tunnel sections on certain rail lines. Those are the known gaps, and Docomo is the network most likely to hold in them. What has changed is that no travel eSIM sold for Japan offers a route to it. Not one of the six names Docomo, so if those gaps are on your itinerary the only reliable answer is a local Docomo SIM.

The national average across networks is 50 Mbps, which is more than adequate for anything a traveller does.

Value at volume

Airalo and Saily are effectively tied at both sizes. Nomad sits below both, and its 50 GB for 30 days at $35 is the only plan in Japan under a dollar a gigabyte — Airalo and Saily sell nothing larger than 20 GB here. For heavy use by the day rather than the gigabyte, Nomad's unlimited plans are verified at $11 for 3 days, $25 for 7, $41 for 14 and $49 for 21, and Airalo's at $11.50 for 3 days, $17 for 5, $27 for 7 and $69 for 30.

Verdict

City trip, one to two weeks, moderate data: any of Saily, Airalo or Nomad will do — none of the three names the network it rides, and in the cities that hardly matters. Buy on price, which now means Nomad: $7 for 3 GB, $16 for 10 GB, $23 for 20 GB, all verified and all the cheapest at their size.

Going rural — Hokkaido, the Alps, the outer islands: buy a local Docomo SIM at the airport for around $12. This used to read "Holafly is the only eSIM in our data on Docomo, or buy a local SIM"; Holafly names no network, so the eSIM half of that choice no longer exists. This is the one decision on the page worth thinking about.

Need to tether a laptop: not Holafly, which has no hotspot in Japan. That combination — rural travel plus tethering — points at a local SIM.

Full plan-by-plan pricing is on the Japan hub.