For most trips to Japan, a fixed-data eSIM on NTT Docomo is the best value: 10 GB for 30 days costs $7.00 with Code eSIM, against $16.50 with Ubigi and $18.00 with Airalo on 9 October 2026. If you stream video every day, Code eSIM’s $19.00 unlimited week on Docomo has had no daily speed cap since 23 October 2026, like Holafly’s $27.50 week, while Airalo’s $26.50 week slows down after 3 GB a day. None of these give you a Japanese phone number; for that, Mobal sells voice and data plans on Docomo.
Most “best Japan eSIM” lists rank brands without showing what you pay. Below are four providers’ own prices for the same trips, the networks they use, and the catch behind each “unlimited” plan. We sell Japan eSIMs ourselves, so we list our weak points too.
Quick picks by trip
| Your trip | What to buy at Code eSIM | Price |
|---|---|---|
| A stopover or one busy day | Day pass, 1 GB for 1 day | $1.99 |
| One week: maps, trains, messaging, photos | 10 GB for 30 days | $7.00 |
| Two weeks, or lots of photo uploads | 20 GB for 30 days | $11.80 |
| A week of daily video, no daily cap | Unlimited for 7 days | $19.00 |
| A month of heavy use | 50 GB for 30 days | $22.99 |
| One to three months | 35 GB for 60 days on 5G | $24.84 |
| You need a Japanese phone number | Mobal voice and data plan | From ¥1,650 a month |
Japan eSIM prices compared
These are the prices on each provider’s own Japan page on 9 October 2026, in US dollars. Saily blocked our automated check with a verification page, so it is not included.
| Plan | Code eSIM | Airalo | Ubigi | Holafly |
|---|---|---|---|---|
| 5 GB, 30 days | $5.30 | $11.00 | Not checked | Unlimited only |
| 10 GB, 30 days | $7.00 | $18.00 | $16.50 | Unlimited only |
| 20 GB, 30 days | $11.80 | $25.00 | Not checked | Unlimited only |
| Unlimited, 5 days | $13.00 | $17.00 | Not checked | $20.50 |
| Unlimited, 7 days | $19.00 | $26.50 | Not checked | $27.50 |
| Unlimited, 10 days | $23.00 | $34.50 | Not checked | $36.50 |
On fixed data, the gap is large: our 10 GB plan costs less than half of Airalo’s or Ubigi’s. On unlimited plans the gap is smaller, and the speed rules matter more than the price. Every plan we sell for Japan, with its network and speed limit, is listed on our Japan eSIM page.
Networks, speed limits and hotspot
| Code eSIM | Airalo | Ubigi | Holafly | |
|---|---|---|---|---|
| Network | NTT Docomo on most plans; KDDI 5G on the KDDI plans | SoftBank and KDDI | KDDI and NTT Docomo | KDDI and SoftBank |
| Unlimited speed rule | No daily allowance since 23 October 2026; fair-use rules may apply | Up to 20 Mbps for 3 GB a day, then 1 Mbps | Not checked | No daily allowance; Fair Usage Policy for up to one day |
| Hotspot | Supported on every Japan-only plan; on the KDDI unlimited plans, up to 1 GB less than the number of days in total | Not stated on the plan page | Not checked | Up to 1 GB a day |
| Top-ups | Not on the Docomo plans; buy a new plan | Yes | Yes | Not stated |
| Phone number | No, data only | No, data only in Japan | Not checked | No, data only |
Docomo is widely reported to have the broadest coverage in Japan, which matters in the countryside and the Japanese Alps more than in Tokyo. We compared the networks in detail in Japan eSIM: Docomo, SoftBank, KDDI or Rakuten.
The catch behind each option
- Code eSIM: our day passes drop to 256 kbps after their daily 1, 2 or 3 GB, which is too slow for video, and the network’s fair-use rules may apply to very heavy use of the unlimited plans. Our Docomo plans count 1 GB as 1,000 MB and cannot be topped up. We are also a smaller store, with far fewer independent reviews than the big brands.
- Airalo: fixed data costs more than twice ours for the same 10 GB. The unlimited week slows to 1 Mbps after 3 GB a day.
- Ubigi: $16.50 for 10 GB is cheaper than Airalo, and its page lists both KDDI and Docomo. We only checked its 10 GB plan.
- Holafly: unlimited only, so a light user pays $27.50 for a week that 10 GB would cover for $7.00. Hotspot sharing is limited to 1 GB a day.
Our explainer on whether unlimited eSIM data is really unlimited covers these speed rules across more brands, and Airalo vs Holafly compares the two big brands in four countries.
How much data you need in Japan
Maps, train apps, messaging and some social media use about 500 MB to 1 GB a day. That makes 10 GB enough for a week for most travellers, and 20 GB enough for two. Video calls, streaming and uploading videos can use 1 to 3 GB an hour, which is when unlimited data starts to make sense. Our travel data guide lists app-by-app numbers.
Prices for every data size, from the $1.99 day pass to 50 GB at $0.46 per GB, are in the next section. For long stays, Japan eSIM: unlimited data vs 30-day plans compares a month of each.
Cheapest Japan eSIM by data size
Our Japan-only plans come in lengths from 3 to 30 days, and the shortest is the cheapest, so pick the shortest plan that covers your trip. These are the cheapest at each size in our catalogue on 27 October 2026; all route data through Japan and none can be topped up, so buy a little more than you think you need.
| You need | 3 days | 30 days | Per GB, 30 days |
|---|---|---|---|
| 1 GB | $3.09 | $3.49 | $3.49 |
| 3 GB | $3.89 | $4.29 | $1.43 |
| 5 GB | $3.99 | $5.30 | $1.06 |
| 10 GB | $5.59 | $7.00 | $0.70 |
| 20 GB | $9.09 | $11.80 | $0.59 |
| 30 GB | $11.99 | $14.89 | $0.50 |
| 50 GB | $16.99 | $22.99 | $0.46 |
Day passes give 1 GB a day at high speed, then 256 kbps, and only pay off for a single day: a one-day pass is $1.99. Seven days of passes cost $5.89, while 5 GB for 7 days costs $4.49 at full speed, and ten days of passes cost $7.00, against $6.39 for 10 GB over 10 days.
Visiting Korea or China too?
One regional plan can cover several countries, but single-country plans are usually cheaper per GB. We compared both for Japan and Korea and for Japan, Korea and China.
Before you buy
- Check that your phone supports eSIM and is unlocked on our compatibility list.
- Install the eSIM at home on WiFi, then turn on the eSIM line and data roaming when you land. The install guide has the steps for iPhone and Android.
- Keep your home SIM on for calls and texts if you need bank verification codes.
- Still deciding against pocket WiFi? See eSIM vs pocket WiFi.
Every Japan plan in one place: our Japan local eSIM page recommends an NTT Docomo or KDDI 5G plan from your trip length and daily use, and lists every price. Weighing an eSIM against renting a router? See Japan eSIM vs pocket Wi-Fi.
Frequently asked questions
What is the best eSIM for Japan?
For most travellers, a fixed-data plan on NTT Docomo: 10 GB for 30 days cost $7.00 with Code eSIM on 9 October 2026, against $16.50 with Ubigi and $18.00 with Airalo. If you stream video for hours every day, our unlimited week at $19.00 and Holafly’s at $27.50 have no daily speed cap.
How much does a Japan eSIM cost?
On 9 October 2026, a one-day pass cost $1.99, 5 GB for 30 days $5.30 to $11.00, 10 GB for 30 days $7.00 to $18.00, and an unlimited week $19.00 to $27.50, depending on the provider.
Which network is best in Japan, Docomo, SoftBank or KDDI?
All three cover cities and main train lines well. NTT Docomo is widely reported to have the broadest coverage in rural and mountain areas, so it is the safer choice outside the big cities. Most of our Japan-only plans run on Docomo, and we also sell KDDI 5G plans.
Is unlimited data worth it in Japan?
Only if you use more than about 3 GB a day. Our unlimited week costs $19.00 with no daily speed cap, while 10 GB for 7 days costs $6.09 and covers a typical week. Holafly’s unlimited week costs $27.50.
Can I get a Japanese phone number with an eSIM?
Not with the data plans compared here. Mobal sells voice and data eSIMs with a Japanese number on the Docomo network, from ¥1,650 a month according to its site. With a data-only eSIM, calling apps still work and your home SIM can keep receiving texts.
Should I install my Japan eSIM before I fly?
Yes. Install it at home on WiFi so you can fix any problem before you leave, then switch on the eSIM line and data roaming after you land. Most of our Japan plans start on first data use in Japan; the three IIJ plans on 5G start when installed, so install those just before you leave.
Count your gigabytes once before you buy, and the right plan is usually obvious.
Last reviewed 9 October 2026; our unlimited, network and hotspot details updated 23 October 2026. Airalo, Ubigi and Holafly prices and terms come from each provider’s own Japan page on that date, in US dollars, and Mobal’s from its Japan eSIM page; they change and can vary by promotion. Our prices and speed limits come from our catalogue on the same date; product pages are authoritative. Airalo, Ubigi, Holafly, Mobal and Saily are trademarks of their owners; this article is independent of them.