You have three ways to get data abroad, and they fail differently
Carrier roaming is the one that needs no effort and costs the most. A local SIM bought on arrival is the cheapest per gigabyte and costs you an hour and a queue. A travel eSIM sits between them: set up before you fly, working the moment you land, at a price above a local SIM and well below roaming.
Which one is right depends less on price than on how much friction you will tolerate at the end of a flight.
Roaming is worth checking before you assume it is bad
Some carriers now include a daily roaming allowance across a list of countries, and some charge painful per megabyte rates outside it. These differ so widely between carriers that the only useful advice is to look at your own plan before you buy anything.
If your plan already covers your destination at a fair daily rate for a short trip, an eSIM adds cost and a setup step for no gain.
A local SIM is cheapest and costs you your arrival
Buying a SIM at the destination usually gives the most data for the money, sometimes several times more than a travel eSIM.
The price is the arrival. You queue at a kiosk, you often need your passport, the shop may be landside after you have already left the secure area, and you have no data while you work out where it is. In some countries registration takes a day.
An eSIM trades a little money for the first hour of your trip
A travel eSIM is installed before you fly and switched on when you land. You walk off the plane with maps, ride hailing and messaging already working.
That is the whole proposition. You pay somewhat more per gigabyte than a local SIM to avoid arriving without a connection.
A free trial lets you test the network before you commit to any of this
The awkward part of buying a travel eSIM in advance is that you cannot tell whether the provider's partner network actually works at your destination until you are standing in it.
A free trial answers that. Nomad gives new accounts 1 GB for 3 days with no card needed. Our comparison table lists every provider we track with the conditions attached.
You probably do not need one for a short trip inside your own region
If your carrier includes your destination, if the trip is two or three days, or if you will be on hotel and cafe wifi most of the time with offline maps downloaded, an eSIM solves a problem you do not have.
Download offline maps either way. It is free and it removes most of the panic from landing without data.
You do need one when being offline would cost you real money
Book a connecting transfer, meet someone at a specific place and time, drive a hire car in an unfamiliar city, or travel somewhere your carrier charges by the megabyte, and arriving connected stops being a convenience.
In those cases install a travel eSIM before you fly, and use a free trial first if you have time, so you know the network holds before you rely on it.
Your phone has to support it, and that is the first thing to check
Everything above assumes an eSIM capable, carrier unlocked phone. Most phones sold since 2019 qualify, with real exceptions.
Our guide on which phones support eSIM has the one minute check that beats any model list.