JWT Decoder
Decode, inspect, and encode JSON Web Tokens. Header, payload, signature - all client-side.
Examples
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eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0…
Header
Payload
Signature (raw)
Header JSON
Payload JSON
Output JWT
How it works
A JWT consists of three Base64URL-encoded parts separated by dots: header.payload.signature. The header specifies the algorithm (alg) and token type. The payload contains claims. The signature
verifies the token hasn't been tampered with.
This tool decodes the header and payload locally (no signature verification). For signature verification you need the secret or public key.
Reference: RFC 7519 - JSON Web Token
Security: This tool does not verify JWT signatures. A decoded payload is not proof the token is valid. Always verify the signature server-side before trusting claims.
Send output to…
Tool piping coming in a future phase.