Online OAuth Token Inspector

Inspect and analyze OAuth tokens to understand their structure, claims, and validity. Our tool supports access tokens, refresh tokens, ID tokens (OpenID Connect), and bearer tokens commonly used in OAuth 2.0 authentication flows.

Features:

Multi-Token Support: Analyze access tokens, refresh tokens, ID tokens, and bearer tokens.
Claims Analysis: View all claims including scopes, audience, issuer, and custom claims.
Expiration Detection: Automatically check if tokens are expired or still valid.
Scope Inspection: See granted scopes and permissions in a readable format.
Privacy First: All inspection happens locally in your browser - tokens never leave your device.

1. Understanding OAuth Tokens

OAuth 2.0 uses different types of tokens for different purposes. Access tokens grant access to protected resources, refresh tokens obtain new access tokens, and ID tokens (in OpenID Connect) provide user identity information.

2. Access Token vs ID Token

Access Token: Used to access APIs and protected resources. Contains scopes that define what actions are allowed.
ID Token: Contains user identity claims (name, email, etc.). Used in OpenID Connect for authentication.

3. Common OAuth Claims

scope: Permissions granted to the token
client_id: The application that requested the token
aud: Intended audience (API or resource server)
iss: Authorization server that issued the token
exp: Token expiration timestamp
iat: Token issue timestamp

4. OAuth 2.0 Grant Types

Authorization Code: Most secure, used by server-side apps
Client Credentials: Machine-to-machine authentication
Implicit: Deprecated, previously used for SPAs
Resource Owner Password: Legacy, use only for trusted apps
PKCE: Enhanced security for public clients

5. Security Considerations

Always treat tokens as sensitive credentials. Use short-lived access tokens with refresh tokens. Validate tokens server-side before trusting claims. Implement proper token storage and revocation strategies.

This OAuth Token Inspector helps developers debug authentication flows and understand token contents.

100% browser-based analysis ensures your tokens remain private and secure at all times.

Related Tools

OAuth 2.0 and OpenID Connect Deep Dive

OAuth 2.0 Overview:

OAuth 2.0 is the industry-standard protocol for authorization. It enables applications to obtain limited access to user accounts on HTTP services. OAuth 2.0 focuses on client developer simplicity while providing specific authorization flows for web, desktop, and mobile applications.

OpenID Connect (OIDC):

OpenID Connect is an identity layer built on top of OAuth 2.0. While OAuth 2.0 handles authorization (what you can access), OIDC handles authentication (who you are). OIDC introduces the ID token, which contains claims about the authenticated user.

Token Validation Checklist:

✓ Verify the token signature using the correct key
✓ Check the token hasn't expired (exp claim)
✓ Validate the issuer (iss) matches expected value
✓ Confirm audience (aud) includes your application
✓ Verify required scopes are present
✓ Check token wasn't issued in the future (iat)

Common OAuth Providers:

• Google OAuth 2.0
• Microsoft Azure AD / Entra ID
• Auth0
• Okta
• Amazon Cognito
• GitHub OAuth
• Facebook Login

Debugging OAuth Flows:

When debugging OAuth issues, inspect tokens to verify correct scopes, check expiration times, validate issuer and audience claims, and ensure the token structure matches your expectations. This tool helps visualize all these components for easier troubleshooting.