5G in Japan for Tourists: What Speed to Really Expect

All four Japanese mobile networks run 5G, and 5G population coverage reached 98.6% nationwide at the end of the 2025 fiscal year, according to the Ministry of Internal Affairs and Communications. In the carriers' own measurement programmes, typical 5G download speeds in big cities sit somewhere between roughly 50 and 400 Mbps. That is far more than you need for maps, messaging and video — which is why, for most travellers, whether an eSIM is 5G or 4G-only barely changes the trip.

The honest summary: 5G in Japan is a nice-to-have, not a deciding factor. Data allowance, throttling rules and which carrier your eSIM roams on matter much more.

Which Japanese networks have 5G

There are four network operators in Japan. Every travel eSIM sold for Japan is roaming on one or more of them — no eSIM company builds its own towers here.

The Ministry of Internal Affairs and Communications figure of 98.6% is the four carriers' areas combined, and prefecture-level coverage ranged from 89.2% to 99.9%. The national target for 2030 is 99%, both nationally and in every prefecture.

Note what "population coverage" means: it counts where people live, not where you will be walking. A mountain trail, a rural bus route or a ferry crossing can sit outside 5G while the town it belongs to counts as covered.

Why the 5G icon does not always mean fast

This is the single most useful thing to understand before you arrive.

All three big carriers state on their own pages that they expanded nationwide 5G by converting existing 4G frequencies to 5G. au calls it NR転用 and says reusing existing base station equipment "makes 5G area conversion possible sooner". SoftBank describes the same converted spectrum as reaching wide areas and working in buildings and underground.

Converted spectrum is genuinely 5G in a technical sense, and your phone will show the 5G icon. But it is narrow spectrum inherited from 4G, so the speed you get is often close to good 4G rather than the headline 5G numbers.

The fast layer is Sub6 (3.7–4.5 GHz), which au defines as the bands that "contribute to high-quality — high-speed, high-capacity, low-latency — 5G communication". au publishes lists of the commercial districts where Sub6 is live, and as of January 2026 they include the places you would guess: Shibuya, Shinjuku, Tokyo and Ginza stations; Umeda, Namba and Osaka stations; central Kyoto; Hakata and Tenjin in Fukuoka.

Above that sits 5G SA (standalone), which au says lets users get fast 5G without depending on congested 4G infrastructure. And above that, millimetre wave at 28 GHz — very fast, very short range, and by SoftBank's own description mostly for stadiums and events. Do not plan a trip around mmWave.

What speed the carriers actually measure

Japanese carriers must publish "effective speed" results measured under a government methodology: fixed measurement points across ten cities, three measurements per point, midday to 6 p.m. in commercial districts and 3 p.m. to 9 p.m. in residential areas. The published range is the middle half of results — roughly the 25th to 75th percentile — so it is a realistic band rather than a marketing peak.

Treat this as a sanity check, not a league table. The carriers use different cities, different devices and slightly different measurement windows, so the numbers are not directly comparable to each other. au measured in Tokyo's 23 wards, Sapporo, Niigata, Tsu, Kyoto, Hiroshima, Yamaguchi, Kitakyushu, Kumamoto and Saga; docomo used Tokyo's 23 wards, Sendai, Osaka, Hiroshima, Hamamatsu, Shizuoka, Kumamoto, Yamagata, Kofu and Matsue.

Two more things to keep in mind. These are measurements of the carriers' own retail customers' experience, and a roaming eSIM may be treated with lower priority on a busy cell. And your own result at Shibuya Crossing on a Saturday evening will not look like a median.

Which travel eSIMs get 5G and which are 4G only

Providers state this on their own pages, and the wording varies. Here is what each company says, taken from its own site as of 2026-08.

The IIJmio line is the clearest example of why you should read spec pages rather than homepages: the same company sells a 5G/4G plan and a 4G-only plan side by side. If 5G matters to you, that distinction is the thing to look for — and it is usually written in the plan's fine print, not the headline.

Airalo also publishes the most useful caveat in the industry: it "can't always guarantee 5G coverage, even if you're using a supported device and are connected to a supported network," because the local signal may not be strong enough. Every provider is in the same position. None of them controls the towers.

Does 5G actually matter for maps and video?

Compare the carrier speed ranges above with what apps ask for.

Japanese 4G routinely delivers well above the 5 Mbps that Full HD streaming needs. So 5G changes almost nothing for the things travellers actually do: navigating to a restaurant, scanning a QR menu, uploading photos, video-calling home, checking train times.

Where 5G does earn its place is bulk transfer and congestion. Uploading a long 4K clip, downloading a large offline map pack in a hotel lobby, or getting a usable connection inside a packed station concourse — those are the moments the extra capacity shows up. That is also exactly where carriers have concentrated their Sub6 build-out.

One caveat that matters more than 5G: throttling. Ubigi's unlimited plan reduces to 2 Mbps after 60 GB. Sakura Mobile's capped plan drops to 200 kbps after 3 GB a day, which is slow enough to hurt. Holafly applies a fair-use restriction for up to one day at a time. A 4G plan with generous full-speed data will beat a 5G plan that throttles you on day three.

City versus countryside: what to expect where you go

• Central Tokyo, Osaka, Kyoto, Nagoya, Fukuoka, Sapporo. Sub6 5G is live in the main station and shopping districts on au's published lists, and the other carriers follow similar priorities. Expect fast, and expect it to sag during evening rush at the busiest interchanges.
• Regional cities and suburbs. Usually a 5G icon, often on converted 4G spectrum. Speeds behave like strong 4G. Perfectly fine for everything on the table above.
• Shinkansen and express trains. Signal drops in tunnels regardless of technology. Download your route, tickets and offline maps before boarding.
• Rural areas, mountains, national parks, small islands. Assume 4G, and assume patches of nothing. Coverage differs by carrier here more than anywhere else, so an eSIM's underlying network matters — docomo has historically had the widest rural reach, and Rakuten Mobile states its own 5G is limited-area only.
• Indoors, basements, older buildings. Converted 4G spectrum penetrates better, which is why SoftBank highlights it for indoor and underground use. You may hold a 5G icon in a basement mall while the actual speed is modest.

How to check what you are getting

Turn on 5G in your phone settings — on iPhone, under Cellular Data Options; on Android, under network mode. Some phones default to "5G Auto" or a battery-saving mode that prefers LTE, which is fine in practice but explains a missing icon.

If speeds feel slow, toggle Airplane mode for ten seconds to force a fresh cell attachment before assuming the eSIM is faulty. And before you buy, check the provider's own plan page for two lines: which network it roams on, and whether the plan says 5G or 4G/LTE only.

FAQ

Do I need 5G in Japan as a tourist?
No. Japanese 4G comfortably exceeds the 5 Mbps Netflix recommends for Full HD and the 5 Mbps YouTube recommends for 1080p. Choose your eSIM on data allowance, throttle rules and network first.

Which carrier has the best 5G for visitors?
There is no single answer, and the carriers' published effective-speed results are not directly comparable because they use different cities and devices. In the January–March 2026 rounds, au reported 145–414 Mbps downloads on iOS and docomo reported 75–373 Mbps. Both are far more than travel apps need.

Why does my phone show 5G but feel slow?
Most likely you are on 5G built from repurposed 4G spectrum, which all three major carriers say they used to reach nationwide coverage quickly. It is real 5G, but the fast Sub6 layer is concentrated in busy commercial districts.

Will my phone work with Japanese 5G?
Most recent unlocked 5G phones connect to Japanese Sub6 networks. Millimetre wave at 28 GHz is deployed in limited spots such as stadiums and open outdoor venues, and is not something to plan around. If your phone does not pick up 5G, it will fall back to 4G, which is widely available.

Is unlimited data really unlimited on these eSIMs?
Not in the strict sense. Providers publish fair-use rules on their own pages — Ubigi lists 60 GB at full speed then 2 Mbps, Sakura Mobile's capped plan drops to 200 kbps after 3 GB per day, and Holafly says restrictions can apply temporarily for up to one day. Read the plan page before buying.

Sources

• 5Gの整備状況（令和7年度末）の公表 — Ministry of Internal Affairs and Communications (Japan) (accessed 2026-08-24)
• 実効速度について | エリア | au（iOS） — KDDI (au) (accessed 2026-08-24)
• 実効速度について | エリア | au — KDDI (au) (accessed 2026-08-24)
• 実効速度計測結果 | 通信・エリア | NTTドコモ — NTT docomo (accessed 2026-08-24)
• 「総務省実効速度調査」計測手法／計測結果 — SoftBank (accessed 2026-08-24)
• 5Gについてもっと知りたい | エリア：スマートフォン | au — KDDI (au) (accessed 2026-08-24)
• 5Gをご利用いただける商業地域 | エリア：スマートフォン | au — KDDI (au) (accessed 2026-08-24)
• 5G SA | サービス・機能 | au — KDDI (au) (accessed 2026-08-24)
• docomo 5G | 通信・エリア | NTTドコモ — NTT docomo (accessed 2026-08-24)
• 5Gを実現するネットワーク技術 — SoftBank (accessed 2026-08-24)
• エリア | 楽天モバイル — Rakuten Mobile (accessed 2026-08-24)
• Can I use 5G with my eSIM? — Airalo (accessed 2026-08-24)
• Japan eSIM (Moshi Moshi) — Airalo (accessed 2026-08-24)
• eSIM Japan Unlimited data — Ubigi (Transatel) (accessed 2026-08-24)
• Japan Travel SIM (PREPAID SIM) — Internet Initiative Japan (IIJmio) (accessed 2026-08-24)
• Best Unlimited 5G Prepaid eSIM for Japan — Sakura Mobile (accessed 2026-08-24)
• eSIM Japan with unlimited data — Holafly (accessed 2026-08-24)
• Internet connection speed recommendations — Netflix (accessed 2026-08-24)
• System requirements for YouTube — Google (YouTube) (accessed 2026-08-24)