JWT Decoder

What is a JWT?

JSON Web Tokens (JWT) are a compact, URL-safe way to represent claims between two parties. They're widely used for:

• Authentication — session tokens after login (OAuth 2.0, OpenID Connect)
• Authorization — role-based access control via claims
• API security — stateless request authentication
• Single Sign-On (SSO) — cross-domain identity sharing
• Information exchange — digitally signed JSON payloads

A JWT has three parts separated by dots: header.payload.signature. This tool decodes the first two (which are Base64-encoded JSON) and shows the signature info.

Note: This tool only decodes — it does not verify signatures. Never paste production tokens with real secrets into any online tool.