Quick answer
- For a month in Japan, validity matters as much as data. A big plan that expires after 7 days doesn't help on day 20.
- Compare plans valid for at least 30 days. Consider recurring monthly plans for longer stays, and unlimited only if you use a lot of data.
- Staying several months? See when a local SIM makes more sense.
For a month in Japan, the plan’s validity matters as much as its data allowance. A large plan that expires after seven days does not help on day twenty. This guide covers the plans we list that last at least 30 days, recurring monthly plans, unlimited data for a month, and when a local SIM suits a longer stay better.
Prices below come from our provider plan list, checked against each provider’s own Japan page. Prices change, so check the total, currency and terms before buying.
30-day Japan eSIM plans compared
We’re run by the team behind Wanderly and earn money from Wanderly purchases. Read our full disclosure.
Every price is for exactly 30 days. Fixed-data columns match the allowance too. A missing quote does not mean the provider sells no longer plan; check its review and current catalogue.
| Provider | 10GB30 days | 20GB30 days | Cost / GB20GB plan | Unlimited30 days | Hotspot | Phone number | Japan network |
|---|---|---|---|---|---|---|---|
| WanderlyOur own storeChecked · Source | $8.9930 days | $12.9930 days | $0.65 | Not listedfor exactly 30 days | Supported on the opened 5GB 7-day and 5GB 5-day plans. The opened 2GB 15-day, 10GB 30-day, 12GB 4-day and 21GB 7-day plans say to check terms | Data-only standard plans; calls & texts available on select plans | NTT Docomo and IIJ on the 5GB 7-day plan; other plans can list only 3G/4G/5G |
| AiraloRead review of AiraloChecked · Source: Airalo Japan page | $18.0030 days | $25.0030 days | $1.25 | $69.00Unlimited / 30 days · fair use applies | Allowed on unlimited packages, per Airalo’s fair-use policy; not stated for fixed packages on the Japan page | Data-only; no phone number on the Japan packages | SoftBank / KDDI (au) / Rakuten on current Moshi Moshi listings; check the selected package |
| UbigiRead review of UbigiChecked · Source: Ubigi Japan page | $16.5030 days | Not listedfor exactly 30 days25GB option in review | — | $65.00Unlimited / 30 days · fair use applies | Data sharing allowed, per the plan pages | Data-only service | KDDI (au) / NTT Docomo; some plans also list SoftBank |
| SailyRead review of SailyChecked · Source: Saily Japan page | $17.9930 days | $24.9930 days | $1.25 | $71.99Unlimited / 30 days · fair use applies | Included on every Japan plan, per Saily’s Japan page | Data-only; a separate US number can be added for calls and texts | KDDI (au) / SoftBank |
| HolaflyRead review of HolaflyChecked · Source: Holafly Japan page | Not listedfor exactly 30 days | Not listedfor exactly 30 days | — | $73.90Unlimited / 30 days · fair use applies | Capped at 1GB/day of sharing (e.g. 7GB on a 7-day plan) | Data-only; no Japanese phone number | KDDI / SoftBank |
| NomadRead review of NomadChecked · Source: Nomad Japan page | $16.0030 daysSale price · regular $18.00 | $23.0030 daysSale price · regular $26.00 | $1.15 | Not listedfor exactly 30 days | Supported, per Nomad’s Japan FAQ | The Japan plans we checked are data-only; Nomad says some eSIMs include a number | KDDI (au) / SoftBank |
The table answers a duration question: which listed packages remain valid for at least a full month? Read the displayed allowance and expiry together. A provider without a qualifying recorded offer is not evidence that it has no such product in its wider catalogue.
For a high-data month, compare larger fixed allowances and unlimited packages using the same 30-day requirement. Avoid assuming a seven-day 50GB plan is suitable just because the allowance looks large. The main Japan eSIM comparison covers overall provider selection; this guide focuses on expiry, recurring billing and the requirements that arise on a longer stay.
How much data do you need for a month?
Using the same planning assumptions as our plan picker, a month of light use (maps and messages, about 0.3GB a day) comes to around 9GB. Moderate use with photos and social media (about 0.75GB a day) comes to around 22.5GB. Heavy use with regular video and sharing (about 2GB a day) comes to around 60GB.
Long stays change habits: reliable apartment WiFi can lower mobile use, while tethering a laptop for work can raise it sharply. The Japan data calculator builds an estimate from the apps you use, and our guide to what a Japan eSIM costs shows how the price changes across trip lengths.
Find a plan for 30 days
A plan for your itinerary
Find the cheapest suitable plan
Tell us how long you’re going and how you use your phone. The result compares every listed provider equally.
Lowest listed price for your inputs
Wanderly $18.99
30GB / 30 days · 30-day trip · 22.5GB estimated use
One fixed-data plan with enough allowance and validity. Check the package network, hotspot and start rule.
See this Wanderly plan →No listed single plan covers those inputs. Check provider packages directly; we will not silently combine short passes or assume top-ups.
We’re run by the team behind Wanderly and earn money from Wanderly purchases. Read our full disclosure.
How the picker works
Estimates use 0.3GB/day for light, 0.75GB/day for moderate and 2GB/day for heavy use. Allowances are never rounded down. We compare a single plan that covers the full trip; daily passes are not multiplied into unverified packages. Unlimited results have fair-use caveats, and a known daily full-speed cap must cover the estimated daily use.
These usage levels are planning assumptions, not measured results. For a closer estimate, use the Japan data calculator.
Recurring monthly plans
Ubigi offers monthly recurring plans aimed at longer stays. A recurring plan renews each month instead of ending after one validity period, which suits a stay of several months.
Ubigi lists Japan monthly plans with 5GB, 20GB or unlimited data a month. They are not in the comparison above, which covers one-off plans. Before subscribing, check on Ubigi’s own page:
- Commitment. Ubigi’s help center says a monthly plan can be cancelled only after a minimum of three months.
- Cancellation. Check how and when you can cancel if you leave early.
- Renewal date and allowance. Confirm when each month’s allowance resets and whether unused data carries over.
Our Ubigi Japan review covers its networks, hotspot support and one-off plans in more detail.
Unlimited data for a month
Four providers in our list sell a 30-day unlimited plan: Ubigi at $65.00, Airalo at $69.00, Saily at $71.99 and Holafly at $73.90. Nomad’s longest unlimited package is 21 days, and Wanderly’s unlimited figure is a starting daily-pass price rather than a quoted monthly package. We do not multiply short passes into a month.
Unlimited for a month comes with the same caveats as a shorter unlimited plan:
- Full-speed limits. Saily gives 5GB a day at full speed, then up to 1 Mbps. Holafly’s phone data is subject to carrier fair use, and Airalo and Ubigi ask you to check their fair-use terms.
- Hotspot. Holafly caps sharing at 1GB a day, separately from phone data; check it before you plan to work from a laptop. Airalo’s Japan page does not state hotspot terms for fixed packages; its unlimited fair-use policy allows hotspot within a default 3GB a day at full speed.
- No phone number. All four are data-only.
For a heavy user, compare the 30-day unlimited total with the largest fixed-data plan that covers your estimate. Our unlimited data guide and Holafly Japan review go further into those trade-offs.
Top up, or buy a new plan?
A top-up adds data to a plan you already have; a new plan usually brings a fresh allowance and a fresh validity period. If validity is about to end, a top-up may not help unless it also extends the validity. If you have run out of data with weeks left, a top-up may be simpler. Most providers we list describe top-ups or add-ons as available on some or eligible plans, including Wanderly, and Holafly’s extension options need checking for the specific purchase.
Ubigi notes that its eSIM profile is reusable, which can make buying another plan less disruptive than installing a new profile. With other providers, a new plan may mean a new eSIM installation, so allow time for setup.
When a local SIM makes more sense
If you are staying for several months, studying, working or moving to Japan, a Japanese mobile contract or a budget carrier (often called an MVNO) can become the better option. Local plans can include a Japanese phone number and, over long periods, may cost less than repeated travel plans.
The trade-off is paperwork. Local contracts often ask for a residence card, a Japanese address and a local payment method, and some have minimum contract terms. Rules differ between carriers and change, so check the carrier’s own information. For a month or two, a travel eSIM is usually simpler; for longer, it can bridge the gap until you are eligible for a local plan. If a Japanese number is the main reason you are considering a local plan, read whether a Japan eSIM comes with a phone number first. Our Mobal review covers a no-contract monthly voice eSIM sold to visitors.
Activation timing on a long trip
A few days lost at the start can leave you short at the end. Check whether the plan starts on installation or on first connection in Japan, and if your stay runs slightly over 30 days, plan for the final days before you go.
Long-stay eSIM questions
Can I get a Japan eSIM for 30 days?
Yes. Several providers we compare list fixed-data plans with 30-day validity, and Holafly lists a 30-day unlimited plan. Check that the plan validity covers your full stay, including arrival and departure days.
What is the best eSIM for a month in Japan?
It depends on how much data you use. Light users can choose a small 30-day plan, moderate users usually need around 20GB or more, and heavy users should compare the largest fixed-data plans with a 30-day unlimited option.
Do monthly recurring eSIM plans have a contract?
Some do. Ubigi says its monthly plans can be cancelled only after a three-month minimum. Check the commitment length, cancellation method and renewal date before subscribing.
Can I top up a 30-day Japan eSIM?
Many providers offer top-ups on some or eligible plans, but not all. A top-up may not extend the plan’s validity, so check the rules for the exact plan.
Should I get a local SIM for a long stay in Japan?
For several months or longer, a local plan may be cheaper and can include a Japanese number, but it usually needs residence documents and may have a minimum contract. A travel eSIM is simpler for shorter stays.