Smartphones & Cellular Tablets:
Dial (*#06#). If an EID number shows, your device supports eSIM!
Laptops (Windows 10/11):
Open your flyout (bottom-right corner). If Cellular settings are visible, your laptop supports eSIM!
On iOS:
Go to Settings > General > About, scroll to Carrier Lock. If it says "No SIM restrictions", your device is unlocked!
On Android:
Go to Settings > Network & Internet > Mobile Network, turn off Auto network selection. If you see multiple available networks, your device is unlocked! If only one appears, or you get an error, it may be locked.