“Sign in with Google” is convenient. One click, no new password to remember, instant account creation. But that convenience comes with trade-offs worth understanding before you use it everywhere.
How it works
When you use Sign in with Google (or Sign in with Apple, Facebook, etc.), you’re using a system called OAuth. Instead of creating a new username and password on that site, you’re authorizing Google to confirm your identity to the third-party app. The site receives a token from Google and some basic information about you — usually your name and email address, sometimes more depending on what permissions you grant.
You’re not giving that site your Google password. Google acts as the authenticator and doesn’t share the actual credentials. From a password hygiene standpoint, you’re not creating another weak password on another site — that part is good.
The real trade-offs
Your Google account becomes a single point of failure. If your Google account gets compromised, every account you’ve linked to it can potentially be accessed. This is the main argument against using Sign in with Google for everything. A compromised email password used to be bad — now it potentially unlocks dozens of connected services. The mitigation is having an extremely strong Google account with 2FA (ideally a hardware key), but most people don’t go that far.
Google sees which services you use. Every time you log in to a third-party site via Google, that interaction is data. Google knows which apps you use, when you use them, and how often. If you’re trying to limit what Google knows about your behavior, authorizing it as the identity provider for every service you use moves in the wrong direction.
Losing your Google account locks you out of everything connected to it. Google accounts do get suspended — sometimes wrongly, sometimes for automated policy violations. If your account gets suspended and you’ve used Sign in with Google to access 20 other services, you’re locked out of all of them simultaneously while you sort out the Google issue.
Sign in with Apple is meaningfully different
Sign in with Apple has a privacy feature the others lack: it can generate a unique, random email address for each app you connect, hiding your real email from the developer. Your real address stays private, and if that app starts spamming you, you delete the relay address. Apple also says it doesn’t use this data to build an advertising profile, which aligns with their business model (hardware) in a way that Google’s (advertising) doesn’t.
If you’re going to use a social login, Sign in with Apple is the least invasive option — though the single-point-of-failure concern still applies.
When it’s a reasonable choice
For low-stakes apps — a one-off tool, a service you’ll use once, a throwaway account — Sign in with Google is a perfectly practical choice. It avoids creating yet another weak password and reduces the number of credentials you’re managing. The risk is proportional to the sensitivity of the connected account.
For high-value accounts — financial services, healthcare, anything with sensitive data — use a password manager to create a unique, strong password instead. Don’t chain these to a single identity provider.
Audit your current connected apps
Google shows you every third-party app connected to your account. Go to myaccount.google.com → Security → Third-party apps with account access. Review the list. Revoke access to anything you don’t recognize or no longer use. Some of these connections persist indefinitely — an app you authorized years ago may still have read access to your calendar or contacts.
The bottom line
Sign in with Google isn’t dangerous for low-stakes apps and is better than reusing a weak password. But it’s not the right choice for everything. Use a password manager for accounts that matter, audit your connected apps periodically, and if you want a social login, Sign in with Apple is the privacy-friendlier option.