A method of obtaining access tokens directly from the authorization endpoint in OAuth 2.0 without an intermediate authorization code.
Description
Implicit Flow is one of the OAuth 2.0 authorization flows designed primarily for client-side applications, such as single-page applications (SPAs). In this flow, the client application directly receives the access token from the authorization server without needing to exchange an authorization code, which is typical in other flows like Authorization Code Flow. This process is optimized for speed and simplicity, making it suitable for apps where the client cannot keep the client secret confidential, such as browser-based applications. It enables a quicker user experience as the access token is provided immediately after the user authenticates. However, it carries security risks, as the access token is exposed in the URL and can be intercepted by malicious actors. Therefore, it is recommended to use Implicit Flow in scenarios where the security implications are well understood and mitigated.
Examples
- A single-page application like Spotify Web Player uses Implicit Flow to authenticate users quickly and access their music libraries.
- Mobile web applications that require immediate access to APIs without complex backend interactions often implement Implicit Flow for smoother user experiences.
Additional Information
- Implicit Flow is less secure than Authorization Code Flow, making it unsuitable for applications that handle sensitive information.
- As of 2020, the OAuth 2.1 specification recommends using Authorization Code Flow with PKCE (Proof Key for Code Exchange) instead of Implicit Flow for enhanced security.