RoamVault eSIM review 2026: legit, cheap for Japan and Asia?

RoamVault is far cheaper than Airalo, Nomad and Saily in Asia, but is it any good?

On most trips, you watch your mobile data. You buy 5 or 10 GB, save video for the hotel Wi-Fi and hope the plan lasts until the flight home. RoamVault makes a different offer: in Asia its data often costs around half of what Airalo, Nomad and Saily charge, so a big plan fits a small budget.

The brand is little known and sold only on the MobiMatter marketplace, with single-country plans for 18 countries. People often look it up, and its Asian plans are among the ones our readers buy most. Does cheap data also mean slow data? I used RoamVault for a month in Brazil, and this review covers what I saw, what it costs in Asia and what buyers in China say.

My experience with RoamVault in Brazil

I bought RoamVault's Brazil plan, 10 GB for 30 days at $20.99, and used it for a whole month. It never gave me a problem. The plan lists two networks, Claro and TIM, both 5G, and my phone sat on TIM with 5G and roaming switched on.

I installed it on arrival in Brazil. Before the trip I'd saved the QR code from MobiMatter's email as a screenshot. At the airport I joined the Wi-Fi and, on my Xiaomi, went to Settings, Mobile networks, Manage SIM, Add eSIM, Scan QR code, Gallery, and picked that screenshot.

My speed test on fast.com showed 67 Mbps in Florianópolis, on Santa Catarina island, and another run came in at about 80 Mbps. Hotspot worked too.

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RoamVault key facts

How you buy RoamVault

You buy RoamVault on MobiMatter, like any online order. Checkout takes Apple Pay, Google Pay, or a Visa or Mastercard card, and the eSIM lands in your inbox as a QR code right away. You can scan it from another screen, and there's nothing to register beyond that.

Save the QR code as a screenshot, so you're not hunting through email on airport Wi-Fi.

At checkout you choose between 3% off right now and 10% back as MobiMatter credit. That credit only works once your balance reaches $16.00 and covers a whole plan, and it lasts a year from your last purchase. The 3% off suits a single trip, because the 10% only pays if you shop on MobiMatter often.

Credit from our promo code above follows the same $16.00 rule.

Refunds are tight once the eSIM is installed, so read the FAQ below before you buy.

RoamVault prices in Asia: Japan, China, Korea and Southeast Asia

Prices checked on October 1, 2026. Every plan is on our RoamVault plans page.

RoamVault is one of the cheapest eSIMs for China, Japan and the other countries in this table. Our readers most often buy the 50 GB plans for China and Indonesia, which work out to $0.60 per GB.

On the China and Japan plans your traffic leaves through Hong Kong, so websites see a Hong Kong address rather than a local one. On the Indonesia plan they see a Singapore address. Some websites may greet you in another language because of it.

RoamVault also sells plans for Australia, the United States, Morocco, Brazil, Saudi Arabia, Bhutan, Laos and the Seychelles, all on our RoamVault page.

See all RoamVault plans

RoamVault vs Airalo, Nomad and Saily: price comparison

For Japan, RoamVault's 10 GB plan costs $7.99. Airalo charges $18.00 for the same amount of data and Nomad $16.00. Saily asks about $15.00, so you pay about half of what the big brands charge.

In China, 20 GB costs $14.99 with RoamVault and $25.00 with Nomad. Airalo's price for that size is $39.00 and Saily's about $41.00, more than double. On 50 GB plans the difference is smaller but still clear: South Korea costs $29.99 with RoamVault and $39.00 with Nomad. All of these are regular prices for 30-day plans.

What buyers say about RoamVault

In MobiMatter's reviews on Trustpilot, a traveler from Sweden describes 10 days in China: "Roamvault from mobimatter has worked flawlessly. Even in remote areas I've had good speeds and coverage." Google, YouTube and Instagram worked for that traveler without a VPN. A traveler from Germany writes of China that "Coverage was almost always good", "we needed no additional VPN" for Google and WhatsApp, and "The price was also very good." From Italy, a third buyer writes: "it worked well for the most part in Italy. Would recommend."

Check RoamVault prices for your trip

RoamVault plan details: networks, 5G, hotspot and validity

Your 30 days start the first time the eSIM uses data, not when you pay, so you can buy weeks ahead. Just don't wait too long, because "the eSIM will expire if not activated within 2 months of purchase".

China runs on China Unicom with 5G. Indonesia runs on Telkomsel with 5G, plus XL and AXIS on 4G.

Your phone joins one of these networks by itself when you land. The list isn't fixed, though, because "the operator can change the networks the eSIM connects to without notice".

Whether you actually get 5G depends on coverage and your phone, with 4G as the fallback. Hotspot is included on every plan, so a laptop or a second phone can share the data. There's no daily cap or throttling while your data lasts.

When the data runs out, you buy a new plan, because top-ups aren't offered. RoamVault is data only, which means no phone number, calls or SMS.

RoamVault review verdict: a good cheap eSIM for one Asian country

Cheap doesn't mean slow with RoamVault. Travelers who used it in China report good speed and coverage. In Asia, its plans often cost far less than the big names charge.

The brand suits heavy data use on a trip that stays in the same Asian country from start to finish, and a big plan can be shared with a laptop without a slowdown. A route through several countries needs a separate plan for each one, since RoamVault sells no regional plan.

Use CopiedESIMSPOTTER at checkout on your first MobiMatter order.

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