JWT Decoder and Validator API — Decode and Inspect JSON Web Tokens
Decode and inspect JSON Web Tokens (JWT). View header, payload, signature, and validate expiration. Free API.
What is JWT Decoding?
JSON Web Token (JWT) decoding parses the three parts of a JWT — header, payload, and signature — and displays their contents. The API shows the algorithm, token type, claims (issuer, subject, expiration, issued-at), and validates expiration timestamps.
How to Use It
Call GET /api/v1/jwt-validate?token=eyJhbG... Returns { header: object, payload: object, signature: string, valid: boolean, expired: boolean, remaining_seconds: number | null }.
Try it live
Test this endpoint in the interactive console
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Frequently Asked Questions
Does the API verify the signature?
The API decodes and inspects the token but does not verify the signature against a secret key. Signature verification requires knowing the signing key.