What Is SSO (Single Sign-On)?

What Is SSO (Single Sign-On)?

Single sign-on (SSO) lets you use one set of credentials — often an account with a major provider — to sign in to multiple services, instead of creating a separate account and password for each. The familiar "Sign in with [provider]" buttons are a common form of SSO. This article explains what SSO is, how it works, its benefits, and the considerations to weigh, in plain terms.

What SSO Is

SSO, in plain terms:

One login for multiple services: SSO lets you authenticate once with one identity provider and use that to sign in to multiple services, without separate credentials for each.

"Sign in with [provider]": A common consumer form is the "Sign in with [major provider]" option, where you use your existing account with a major provider to sign in to other services.

Reduces separate accounts/passwords: SSO means fewer separate accounts and passwords to create and manage.

How SSO Works

The general mechanism:

An identity provider authenticates you: With SSO, an identity provider (like a major account provider) authenticates you, then vouches for your identity to the services you sign in to.

Services trust the provider: The services you use trust the identity provider to authenticate you, so you do not need a separate password with them.

You authenticate once: You sign in to (or are already signed in with) the identity provider, and can then access connected services without separate logins.

Benefits of SSO

SSO offers advantages:

Convenience: SSO is convenient — fewer accounts and passwords to create, remember, and manage, and quick sign-in to services.

Fewer passwords to manage: With fewer separate passwords, there is less password fatigue and less temptation to reuse weak passwords across services.

Can improve security if the main account is secure: If your identity provider account is strongly secured (strong password and 2FA), SSO can mean fewer weak, separate passwords — potentially improving overall security.

Considerations to Weigh

SSO has tradeoffs to consider:

The main account becomes critical: With SSO, your identity provider account becomes a critical key to your connected services — so securing it strongly (with a strong password and 2FA) is essential. If it is compromised, connected services could be at risk.

Single point of dependence: SSO concentrates dependence on the identity provider — if you lose access to that account, you could lose access to connected services. Ensure good recovery for the main account.

Privacy considerations: Using SSO can share some information between the identity provider and services, and ties your service usage to your main provider account. Consider the privacy implications and what is shared.

Provider availability: You depend on the identity provider's availability for SSO sign-ins.

When SSO Makes Sense (and Alternatives)

Weighing SSO:

When convenient and secure: SSO makes sense for convenience, especially if your identity provider account is strongly secured and you are comfortable with the connection.

Secure the main account: If you use SSO, strongly secure your identity provider account (strong password, 2FA), since it is the key.

Alternative — separate accounts with a password manager: An alternative is creating separate accounts with strong, unique passwords managed by a password manager, which avoids the single-point dependence and some privacy linkage, while still managing passwords easily. For services where you prefer not to link via SSO, this (with temporary email like Temp90 for less-trusted ones) is a good approach.

Mix as appropriate: You can use SSO where convenient and separate accounts where you prefer, based on your priorities.

Frequently Asked Questions

What is single sign-on (SSO)?

Single sign-on (SSO) lets you use one set of credentials — often an account with a major provider — to sign in to multiple services, instead of creating a separate account and password for each. The familiar "Sign in with [provider]" buttons are a common form. It works by having an identity provider authenticate you and vouch for your identity to the services you sign in to, which trust the provider — so you do not need a separate password for each service. SSO reduces the number of separate accounts and passwords you create and manage, offering convenience. Its main consideration is that your identity provider account becomes a critical key to your connected services, so securing it strongly is essential.

Is using "Sign in with [provider]" (SSO) secure?

SSO can be secure, with an important condition: your identity provider account becomes a critical key to your connected services, so it must be strongly secured with a strong password and 2FA. If your main account is well secured, SSO can actually improve overall security by reducing the number of separate, potentially weak passwords you manage. However, if your identity provider account is compromised, your connected services could be at risk, and if you lose access to it, you could lose access to connected services — so good security and recovery for the main account are essential. There are also privacy considerations, since SSO ties your service usage to your main provider account and may share some information.

Should I use SSO or create separate accounts?

It depends on your priorities. SSO offers convenience (fewer accounts and passwords) and can improve security if your identity provider account is strongly secured — but it makes that account a critical single point, ties your usage to the provider, and shares some information. An alternative is creating separate accounts with strong, unique passwords managed by a password manager, which avoids the single-point dependence and some privacy linkage while still making passwords easy to manage (and you can use temporary email like Temp90 for less-trusted services). Many people mix both — using SSO where convenient and separate accounts where they prefer more separation. If you use SSO, strongly secure your identity provider account with a strong password and 2FA.

Conclusion

Single sign-on (SSO) lets you use one set of credentials — often an account with a major provider — to sign in to multiple services, instead of creating a separate account and password for each, with "Sign in with [provider]" buttons being a common form. It works by having an identity provider authenticate you and vouch for your identity to services that trust the provider, so you do not need separate passwords. SSO offers convenience (fewer accounts and passwords to manage), reduces password fatigue and reuse, and can improve security if your identity provider account is strongly secured. But it has considerations: your main account becomes a critical key to connected services (so secure it strongly with a strong password and 2FA), it concentrates dependence on the provider (ensure good recovery), it ties your usage to the provider and shares some information (privacy considerations), and you depend on the provider's availability. SSO makes sense for convenience when your main account is well secured; an alternative is separate accounts with strong, unique passwords in a password manager (with temporary email like Temp90 for less-trusted services), which avoids single-point dependence. Understanding what SSO is, its benefits, and its considerations helps you decide when to use it and how to use it securely.