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At first glance, this seems like a hassle-free solution: users can access the app in a matter of seconds without having to come up with a new password, and app developers can offer a modern and convenient login method.
The advantages of this approach are obvious:
The advantages of this approach are obvious:
- speed and simplicity – registration and login take just a few clicks,
- fewer passwords to remember,
- greater security compared to weak passwords (e.g., when using two-factor authentication via Google).
However, where there is convenience, there are also risks that are not so obvious.
Dependence on third parties
If you decide to offer login only through external providers, you are exposing your application to risk. All it takes is for the platform to decide to change its terms and conditions, introduce new fees, or cancel the integration altogether, and your users will suddenly be unable to log in to the application.
The question of security
At first glance, third-party logins seem more secure than implementing your own passwords, because you are relying on giants who invest huge amounts in security. But:
- A data leak or account misuse at the provider (e.g., a compromised Google account) poses an immediate risk to your application as well.
- If a user shares access to their account (typically a work Google or Microsoft account), someone who shouldn't have access to the application may also have access.
Data ownership and management
When logging in via a third party, you usually provide the application with certain data (name, email address, sometimes more).
- Question for users: Who am I actually entrusting my information to?
- Question for app operators: How dependent am I on the third party providing me with data? What if the scope of data is limited, the API changes, or a fee is required?
Restricting users
Not everyone has a Google, Facebook, or Apple account—or wants to use it for everything. If you only offer external login, you will discourage some users.
Long-term sustainability
Third-party integrations must be continuously updated. Changes to the API, new security standards, or mandatory verification mechanisms may mean that even after years, it will be necessary to invest time and resources in development.
How to do it sensibly
- Combine: offer third-party login, but also classic login (email + password).
- Communicate transparently what data you obtain from the provider and what you use it for.
- Think about a plan B - what happens if the third party changes the rules?
Third-party logins are a great tool for simplifying the user experience, but they must not become the only way to use the application. Speed and convenience can come at the price of dependence on services that are beyond your control.
Are you considering implementing third-party logins in your application? We can discuss it together.
