An eSIM is one of those rare upgrades that’s almost pure win: you land, your phone already has data, and you never again queue for a local SIM with your passport in hand. The only catch is that “eSIM” now covers very different products — buy the wrong one and you’re either rationing megabytes or paying for data you’ll never touch.

Three cover almost everyone.

The sensible default

Airalo

Airalo is the one to reach for first: a marketplace of local and regional data eSIMs across more than 200 countries, cheap, installed before you board. For most trips it’s simply the right answer — buy the country or region pack, switch it on when you land, done.

The catch: packs are sized, so a heavy user can burn through one faster than expected and end up topping up. For normal use, that’s a non-issue.

Best for: most travellers, most trips — the default starting point.

The unlimited one

Holafly

If you tether a laptop, live on video calls, or simply hate watching a data counter tick down, Holafly’s pitch is unlimited data per day on a destination eSIM. It removes the rationing anxiety entirely.

The catch: “unlimited” usually comes with a fair-usage speed cap once you pass a daily threshold, and it’s often pricier than a sized plan you’d never exhaust. Worth it precisely when you already know you’re a heavy user.

Best for: heavy users who’d rather pay more than count megabytes.

The newcomer worth watching

Saily

Saily comes from the team behind NordVPN, and it shows: a clean app and a security-minded bent. It’s younger, the catalogue is newer, but the experience is tidy and the regional plans are competitive — and if you already live in the Nord ecosystem, it slots right in.

The catch: it’s the least battle-tested of the three. Treat it as a strong second opinion rather than the incumbent.

Best for: tidy-app lovers and anyone already in the Nord ecosystem.

“An eSIM is only ever as good as the local network it quietly rides on. Buy the data — but check the signal.”

So which one

Match the plan to the trip, not the marketing: Airalo for the ordinary one, Holafly when you know you’ll be heavy, Saily if you want the newest app and don’t mind being an early adopter. And keep your home SIM active for bank codes — losing your 2FA in another country is its own small disaster. The full method, including the “unlimited” traps and device gotchas, is in our guide on staying connected across borders.