JWT — Free JSON Web Token Decoder by @nap.codes.

By@nap.codes
READYv1.0 · client-side
Client-side · decode only · signature not verified
INPUTEmpty
Length: 0 chars · 0 segments JWT format: header.payload.signature
DECODED
Header (alg + type)
Payload (claims)
Signature (opaque)
Signature verification requires your public key or shared secret — run on your backend, not in the browser.

Decode JWTs without giving them to a server

Paste any JSON Web Token. See the header, payload, and signature — plus human-readable dates for exp, iat, nbf. All local.

Handy jwt.io alternative when you're inspecting production tokens or anything you'd rather not paste into someone else's backend. Uses only browser APIs (base64 + JSON.parse). Nothing sent, nothing logged.

Frequently asked

Is my JWT uploaded?

No. Decoding uses native base64 + JSON.parse in your browser. Zero network traffic.

Why not jwt.io?

jwt.io is great, but it also runs a server for signature verification. For sensitive prod tokens, pure client-side is safer.

Does this verify the signature?

No — verification requires access to your public key or JWKS. Do that on your backend.

What claims are explained?

Standard RFC-7519 claims: exp, iat, nbf, iss, sub, aud, jti.

Free?

Yes, always.