Best Practices for Access, ID, and Refresh Tokens
When building modern applications with OAuth 2.0 and OpenID Connect, developers often get confused about where to store tokens . This decision is crucial because storing them incorrectly can open doors to serious vulnerabilities like XSS or CSRF attacks. Let’s break it down. Understanding the Tokens Access Token → Proves what you can do . It authorizes the client to call APIs on behalf of the user. ID Token → Proves who you are . It carries identity information (name, email, roles) about the authenticated user. Refresh Token (optional) → Used to obtain new access tokens without making the user log in again. Each token has a different lifespan and security sensitivity, so the storage strategy must match the risk. Storage on the User Side (Frontend) 1. Web Applications Best practice : Keep tokens in memory (JavaScript variables). Safer persistence : Use HTTP-only, Secure cookies if tokens must survive page reloads. Avoid : localStorage and sessionStorage for...