The physical SIM cards we've used for decades are slowly being phased out.
With the Pixel 10 series, Google's phones have gone eSIM-only for the first time—at least if you buy them in the US. Apple made the same move with the iPhone 14 in 2022, and now its new iPhone 17 models will operate with eSIMs in a dozen countries, with the slim iPhone Air going eSIM-only everywhere in the world.
But how is eSIM different, and what do you need to do to switch? The good news is that by most measures, eSIM is the superior technology: You can change numbers with a couple of taps on an app rather than waiting for a new card to arrive in the mail, for example. And they're more secure overall. If you've got questions about what they are or how they work, here's what you need to know.
How eSIMs Work
SIM stands for Subscriber Identity Module (SIM), and these little plastic chips you slide into your phone are like your ID badge for getting connected to cellular networks. They show who you are and which carrier you're signed up with, and tell other devices sending you calls and messages where you can be found.
An eSIM is just an embedded version of a SIM: Your ID badge is no longer in physical form, but completely digital inside your phone. Otherwise, it does pretty much the same job for you, giving your phone permission to get connected to the nearest cell tower and enabling calls and messages.
Google has gone eSIM-only with the Pixel 10. Courtesy of Google
Rather than your information being stored on a card, it's written to a specific part of the storage on your phone, with a significant amount of protection around it to prevent tampering. If you decide to switch to a different carrier or a different deal and the eSIM needs to be changed, this is done via software on the phone.