A Google verification code is a temporary sequence, usually six digits long, generated or sent when logging into a Google account protected by two-step verification. This code serves as the second layer of authentication, following the password. Several methods allow for receiving or generating it, and the choice of method directly impacts the level of protection for the account.
TOTP, SMS, or Google prompt: the mechanisms behind the verification code
Not all verification codes are created equal. Understanding their technical workings allows for choosing the method best suited to one’s needs.
The TOTP (time-based one-time password) protocol relies on a shared secret key between the Google server and the device during the initial setup. The Google Authenticator app generates a six-digit code that changes every thirty seconds, without needing an internet connection or mobile network.
The SMS or voice call code travels through the telephone network. This method remains functional, but it is vulnerable to interception (SIM swapping, call redirection). On Google Workspace, administrators can now restrict second-step methods and exclude codes received via SMS or call, deemed less reliable, in favor of security keys or authentication apps.
The procedure to obtain a Google verification code thus depends on the validation mode configured on the account. The Google prompt (push notification on a trusted device) provides a third, smoother option that simply requires approving the login from the associated phone.
Setting up two-step verification on a Google account
Two-step verification is activated from the security settings of the Google account. The process follows a progressive logic that combines the password with a second authentication method.
Configuration steps in the security settings
Access your Google account, then go to the Security section. Select “Two-step verification” and follow the instructions. Google first offers the prompt on the phone, then allows adding other methods.
- Install Google Authenticator (version 6.0 or later on Android, 4.0 or later on iOS) and scan the QR code displayed by Google to link the account
- Add a recovery phone number to receive codes via SMS as a backup solution
- Generate a set of backup codes (ten one-time codes) to keep in a safe place, just like you would keep a passport
Once activated, each new login from an unrecognized device will require the password followed by the verification code.
Synchronizing Authenticator codes between devices
Google Authenticator now allows synchronizing validation codes across multiple devices by signing into your Google account within the app. The codes are encrypted in transit and at rest. Losing a phone no longer means losing access to all your accounts, provided this synchronization was enabled beforehand.
Google backup codes: the often-overlooked safety net
Backup codes are a set of ten one-time codes that can be downloaded from the account’s security page. Each code works only once. When a new set is generated, the old one is automatically disabled.
These codes are useful when the phone is lost, stolen, or inaccessible. Without them, account recovery becomes significantly more complex and may require a lengthy identity verification process.
A point of caution: Google will never ask for a backup code outside of a login procedure initiated by the user. Any solicitation via email or message requesting a backup code is a phishing attempt.
Passkeys and the future of the Google verification code
Since 2023-2024, Google is rolling out passkeys (access keys based on the FIDO/WebAuthn standard). This technology changes the logic of the traditional verification code. With a passkey, validation occurs directly on the trusted device via biometrics (fingerprint, facial recognition) or the device’s lock code.
Specifically, on an account configured with a passkey, there is no longer a need to enter an SMS code or TOTP code at each login. The second step is integrated into the unlocking gesture. For Google Workspace accounts, administrators can mandate the use of passkeys or physical security keys and set a mandatory enrollment period.
Passkeys do not render backup codes obsolete. In the event of losing all trusted devices, backup codes remain the last resort for regaining access to the account. Keeping a printed set in a secure location remains a relevant precaution, regardless of the primary authentication method chosen.
The Google verification code thus coexists with newer technologies. Accounts that have not yet migrated to passkeys continue to rely on Authenticator, SMS, or prompts. The technical recommendation remains clear: prioritize the authentication app or passkeys, keep backup codes updated, and disable SMS as the primary method as soon as a more robust alternative is in place.
