JWT Decoder Online — Free Decode JWT Token Header & Payload
Decode a JSON Web Token in your browser to inspect its header and payload. Signature is NOT validated — debugging only.
Paste a JWT below. Header and payload are decoded from Base64URL locally; the token never leaves the page.
Common use cases
- 1Inspect an OAuth access token to check its expiration, audience and scopes.
- 2Debug a third-party SSO failure by reading the claims the IdP signed.
- 3Verify your app emits the JWT shape you expect before integration testing.
Frequently asked questions
Why isn't the signature verified?+
Verification needs the issuer's public key (RS256 / ES256) or shared secret (HS256). That is an infrastructure decision — use jose / jsonwebtoken with the right key for that. This tool decodes only.
Is my token safe to paste here?+
Decoding runs entirely in your browser; the token never leaves the page. However, an ACTIVE access token still carries your identity — if it is in use, redact sensitive claims after debugging.
Why does my token decode to gibberish?+
It is probably not a JWT. Real JWTs always have three Base64URL parts separated by dots (header.payload.signature). Opaque tokens (random strings) do not decode to JSON.