Security•Client-Side Processing
JWT Decoder
Inspect JWT headers and claims, check expiration, and optionally verify HS256 signatures.
Developer workbench
⌘ / Ctrl + Enter to runConfigure. Run. Inspect.
Secrets remain in memory. JWT signing and verification use HS256; decoded claims are not automatically trusted.
177 input bytes
Output
How to Use JWT Decoder
01
Paste a JWT with three dot-separated segments.
02
Optionally enter the HS256 secret to verify the signature.
03
Run the inspector and review signature and time-claim results.
04
Check issuer and audience separately before trusting a token.
Frequently Asked Questions
Is my secret key or token transmitted over the network?
No. The entire decoding process happens in your browser's local JavaScript environment. No tokens leave your machine.
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