Instabridge

Instabridge started as a WiFi mapping application and evolved into a full eSIM operator with both single-country and multi-country plans. For Japan travel, the service offers four Japan-only eSIM options and eight plans covering multiple Asian destinations, all on a pay-as-you-go basis with no long-term contracts to lock travelers in.

The app heritage means Instabridge retains strong integration with WiFi discovery alongside mobile data, appealing to budget-conscious travelers who want fallback options. There's no minimum purchase or subscription requirement, which works well for short trips or trials.