Roamsim
Roamsim: Low-cost Japan eSIM plans, with unlimited data throttled after 1 GB per day. Ranked #55 of 60 in Japan eSIM Plans by our editors (3.2/10); pricing: From €1.11; best for travelers wanting low-cost daily unlimited data.
At a glance
- Editor score3.2 / 10
- PricingFrom €1.11
- Best forTravelers wanting low-cost daily unlimited data
- Free planNo
- Data typeUnlimited
- Facts checked3 Oct 2026
Where it wins
- One-day unlimited plan listed at €1.11
- QR-code delivery for Japan eSIM plans
- Keep your main number while using a separate data line
Where it doesn't
- Unlimited plan slows to 256 kbps after 1 GB per day
- 4G/5G service depends on plan, device and location
- Requires an eSIM-capable, carrier-unlocked phone
Our verdict on Roamsim
Roamsim sells travel eSIM data plans for Japan, with fixed-data and unlimited options for travelers whose phones support eSIM and are carrier-unlocked. Plans arrive by QR code after purchase, and the eSIM can provide a separate data line while the traveler keeps their main phone number. Japan connectivity uses partner networks; the available 4G or 5G service depends on plan, device and location. Regional Asia and global plans that include Japan are also available, though the listed one-day option is Japan-specific.
The published Japan plan is named Unlimited and costs €1.11 as a one-time charge for one day. It provides the first 1 GB per day at full speed, then reduces speed to 256 kbps; the plan highlights 4G. Roamsim also sells fixed-data Japan plans with varying validity periods. Since activation rules vary by plan, buyers should read the activation note at checkout. For someone needing data for a short visit and comfortable with a daily high-speed allowance followed by slower service, the displayed unlimited option has a low entry price. It is less suited to travelers who need full-speed data beyond that allowance.
This is a travel data service rather than a replacement for a primary phone line: Roamsim describes using the eSIM separately while retaining a main number. QR delivery offers a direct route to adding the plan, but setup still depends on having a compatible, unlocked device and following that plan’s activation timing. An in-app support assistant is available 24/7, and support channels include email and chat. Choose Roamsim if Japan data, QR delivery and a distinct data line match the trip; consider another option if ongoing full-speed use after 1 GB per day is essential.
Roamsim pricing
All 1 Roamsim plans and prices →
Roamsim fact sheet
| Free plan | No |
|---|---|
| Paid from | Not verified |
| Data type | Unlimited |
| Data allowance | Unlimited; first 1 GB/day at full speed, then 256 kbps |
| Validity | 1 days |
| Hotspot support | Not verified |
| Coverage scope | Japan_only |
| Activation timing | First_connection |
| Deployment | Cloud, Mobile |
| Platforms | Web, iOS, Android |
| Support | Email, Live chat · 24/7 |
| Built for | Solo (editorial estimate) |
| Pricing | From €1.11 (source) |
| Website | roam-sim.com |
| Facts checked | 3 Oct 2026 |
Alternatives to Roamsim
- AiraloA broad Japan eSIM lineup with app tracking, low-data alerts, and eligible top-ups.9.3
- Orange TravelA flexible prepaid choice, from a €1 1 GB bundle to larger and unlimited plans.9.1
- Vodafone Travel eSIMJapan data plans range from fixed bundles to unlimited and shared options.9.0
See all Roamsim alternatives →
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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