One country, one question
About this site
Every other Japan eSIM page compares brands. This one compares networks, because in Japan that is the part that decides whether your phone works.
What this site is. A single-country comparison of every travel eSIM sold for Japan, built around the question the buy buttons do not answer: which Japanese carrier are you actually getting. Three quarters of Japan is mountain, NTT Docomo built towers there and the others did less, and that fact decides more about your trip than the logo on the eSIM.
Why Japan needs its own site. Because the answer changes at the city limits. In Tokyo, Kyoto and Osaka every network is excellent and the right eSIM is the cheapest one. In Kamikochi, rural Hokkaido and the Shikoku mountains it is the one on Docomo, and only two of the four brands we can link have it. A general "best eSIM" list cannot make that distinction and does not try.
What it earns. A commission from GigSky, Airalo, Saily and Yesim when you buy through a link. Nothing from Ubigi, Nomad, Mobal or the pocket wifi renters, all of which are recommended somewhere on this site where they are the better answer. The methodology page publishes the rate we get from each brand, which is unusual and is the point.
What it does not do. No sponsored placements, no guest posts, no paid positions in any table. No claim to have run a speed test we did not run. No "unlimited" without the daily cap printed next to it.
How it stays current. Prices are re-pulled monthly and every table carries the date it was checked. Japanese SIM law changed in April 2026 and most English-language guides have not noticed; this one has. Corrections are read by a person and ship in the next update. Send them here.
Sources & freshness: Related: how we test and what we earn · contact · the comparison. Last revised September 4, 2026.