Cybersecurity

What is OAuth?

Quick answer

An open standard that lets users grant an app limited access to their data on another service without sharing their password.

OAuth, explained

When an app asks to connect to your calendar or offers a sign in with a large provider button, it is often using OAuth, typically version 2.0. Instead of handing over your password, you are redirected to the provider, you log in there, and you approve specific permissions, called scopes, such as read-only access to your contacts.

The provider then gives the app an access token that works only for those permissions and can be revoked at any time. OAuth handles authorization; OpenID Connect is a layer on top that adds standardized authentication, telling the app who you are. Implementing OAuth correctly requires care, including validating redirect addresses and protecting tokens, since mistakes can expose user accounts.

Related terms

Guides that mention OAuth