JWT Decoder & Debugger
Decode JSON Web Tokens (JWT) to view their header, payload, and signature. 100% private decoding in your browser.
JWT Decoder & Debugger
Foundry_Core
TheAuthentication Matrix
JWTs are the security currency of the modern web. However, they are opaque by design. Our diagnostics engine deconstructs these Base64URL encoded strings into their component parts (Header, Payload, Signature) without ever sending your sensitive auth data to a server. In an era of high-stakes Security Audits, this tool provides the 'Token Transparency' needed for secure development.
TokenDeconstruction
Base64URL Decoding Matrix
JWTs use a specialized 'URL-Safe' version of Base64. Our engine correctly handles the character swaps and padding logic to extract the JSON payload, ensuring that non-ASCII characters and specialized claims are rendered with 100% accuracy.
The Timestamp Logic
Claims like `exp` (expiry) and `iat` (issued at) are stored as Unix timestamps. Our engine automatically converts these into human-readable local time, allowing you to instantly see if a token is still valid or has expired.