JWT Decoder
Decode and inspect JWT tokens — header, payload, and claims — and verify signatures (HS256/384/512, RS256/384/512, ES256/384/512). All processing happens locally.
Input
JWT token
Output
Decoded JWT
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Leave the key empty to decode without verifying the signature.
FAQ
- What information can I see?
- You can inspect the JWT header (algorithm, type), payload claims (issuer, subject, audience, expiration, issued-at, etc.), and optionally verify the signature using a secret or public key.
- How does signature verification work?
- Provide the secret (for HS256/384/512) or PEM-encoded public key (for RS*/ES*) and the signature is verified using WebCrypto in your browser. Verification requires a secure context (https or localhost).
- Is my token uploaded anywhere?
- No. All decoding and verification happens locally in your browser.