JWT Decoder

Decode JSON Web Tokens to inspect header, payload, and check expiration. Runs entirely in your browser (decode-only, no signature verification).

JWT Token
This tool decodes token data for inspection only. Signature and issuer trust are not validated.
How To Use
  1. Paste a full JWT token in header.payload.signature format.
  2. Click Decode to inspect header and payload claims instantly.
  3. Check expiry status and verify signature separately in your auth stack before trusting the token.
Common Use Cases
  • Debugging expired auth tokens in frontend login flows.
  • Validating role and subject claims during API testing.
  • Inspecting third-party identity provider payloads safely.
How To Use & FAQ

Q: Can this tool verify the JWT signature?

A: No. It decodes token parts for inspection only and does not validate secrets or public keys.

Q: Does this upload my token data?

A: No. Decoding happens locally in your browser session.

Q: Does this support UTF-8 claims (e.g. Korean, emoji)?

A: Yes. Base64url token segments are decoded with UTF-8 support for readable claim values.

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