eSim for dummies

I'm probably going to use Airolo for the first time during a trip to the UK in about a month.

My question is: what does Airolo (eSim) allow me to do? Google maps? GPS? Accessing the internet? Whats App? Do I just turn it on upon arrival in UK?

It will let you use any service that requires Internet access to run, such as web browsing. Google Maps is a data service, so using Airolo will provide Google Maps with an Internet connection so you can see maps. WhatsApp is the same, it goes through the Internet, so if you have either mobile cellular data or a wifi connection it will work.

Seeing your location on a map is slightly different. GPS signals come from satellites, so you don’t need Internet access for that, you need a GPS receiver which practically all smartphones do have. However, to see where you are on a map, the GPS coordinates your phone worked out from the satellite signals needs to be shown on a map, and you do need Internet access for the map. Also, many location services also use wifi to help refine your location when satellite reception is not good (like indoors), so location tends to work more smoothly if wifi is on.

So location services work out where you are using a combination of GPS satellite signals and wifi. To see the determined location on a map, your phone does need Internet access to download the map.

I am sort of new to the eSim thing, but I think what we want to do is disable AT&T as you leave the US to avoid racking up any international charges, and enable the eSim after that or on arrival in the UK.

I used an Airalo eSIM for the first time last month. I used Google maps extensively and talked using WhatsApp. The eSIM did everything I needed. I loaded it before I left home, went in airplane mode during travel and then switched off my usual service and turned on the eSIM when I landed. The one error I made was to not set the eSIM to roaming. I thought at first it was a big failure but when I had time later in the day to do some research I figured it out. So be sure the eSIM is set to roam!

However, to see where you are on a map, the GPS coordinates your phone worked out from the satellite signals needs to be shown on a map, and you do need Internet access for the map.

You can download an offline Google map to your phone when you do have Internet access, and then track your movements on the map using only GPS. The map will have limited functionality without cellular data - directions won't work, etc.

I’ve used eSIMs from Airalo in Turkey, the UK, and Japan. They work great!

I found that watching a few you tube videos about eSIMs was quite helpful.

Thank you thank you for these helpful replies!