Many will tell you that two-factor authentication is more secure without using phone numbers, and Google is putting that wisdom into practice. The internet giant will make phone verification prompts the default for two-step sign-ins for “all eligible users” starting on July 7th unless they’re already using security keys. So long as you’re signed into Google on your phone, you’ll get a notification that asks you to prove it’s really you signing in elsewhere.
You’ll still have the option of different methods (such as SMS codes) if they’re available to you, but you’ll have to choose them.
