SimSmash eSIM Data Plans for Japan

SimSmash does not provide a truly unlimited data eSIM plan for Japan. All plans that include the word “Unlimited” in their name are in fact capped, with daily limits ranging from 490 MB to 10 GB; after that amount the connection speed would be reduced, although the specific throttled speed is not listed.

Travelers who need larger data allowances can choose one of the fixed‑data plans instead. Examples include Japan 50 GB for 30 days for $19.99 USD and Japan 20 GB for 30 days for $9.99 USD, both of which offer high‑speed 5G service and are generally more cost‑effective for heavy data users.

SimSmash does not provide a Japan eSIM plan that includes a phone number or SMS capability. The provider’s Japan catalog consists only of data‑only eSIMs. Travelers who need voice or text services can rely on popular VoIP applications such as WhatsApp, Telegram, or iMessage over the data connection, but it is advisable to confirm that these apps are accessible in Japan before purchasing, as some destinations may block or restrict certain services.

SimSmash offers 13 single‑country data plans that cover Japan, in addition to 18 multi‑country plans that include Japan. The plans span a price range from about $0.89 to $94.99 and provide data caps ranging from 490 MB up to 50 GB, giving travelers several budget and usage options.