Firsty

Firsty offers data roaming in 160+ countries without contracts or activation fees. Its automatic network detection picks the fastest available carrier in each location, which is especially useful across Southeast Asia's crowded mobile market where multiple operators compete. You only pay for the data you actually use, and can activate the eSIM instantly via the app.

Works well for budget-conscious backpackers and business travelers who need flexibility. If you prefer predictable costs, other providers' fixed daily plans might suit you better, but Firsty's pay-as-you-go model rewards light users and gives you transparency about how much you're spending.