Decode a JWT Without the Secret
You can decode a JWT without the secret because the header and payload are only Base64URL encoded. Paste a token to read it. Verification needs the key.
Part of the free JWT Decoder. Runs in your browser — nothing is uploaded.
Decode a JWT Without the Secret
Reading a JWT does not need a secret. The header and payload are plain Base64URL-encoded JSON. The secret or public key is only needed to verify the signature, which proves the token was not tampered with.
Worked example: Decoding needs no key
JWT
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJzdmMtYmlsbGluZyIsInNjb3BlIjoicmVhZDppbnZvaWNlcyIsImlhdCI6MTc2NzIyNTYwMH0.c2lnbmF0dXJl
Decoded token
// HEADER
{
"alg": "HS256",
"typ": "JWT"
}
// PAYLOAD
{
"sub": "svc-billing",
"scope": "read:invoices",
"iat": 1767225600
}
// CLAIM TIMES (UTC)
iat: 2026-01-01 00:00:00 UTCPractical tip
Decoding is not trust. Always verify the signature and the iss, aud and exp claims on your server before acting on a token.
How to use this JWT Decoder
- 1Use the live tool above — it runs entirely in your browser and never uploads your data.
- 2Paste the sample from the worked example, or use your own input.
- 3Copy the result, then adapt the same steps in your editor, script, or pipeline.
Decode a JWT Without the Secret FAQs
Does decoding prove a JWT is valid?
No. Decoding only reveals contents. Validity requires verifying the signature with the correct key and checking claims such as expiry and audience.
Why is the signature not decoded?
The signature is raw binary produced by a cryptographic algorithm. It is not JSON, so there is nothing readable to show without verifying it against a key.
More JWT Decoder pages
- Decode a JWT Token OnlineDecode a JWT token online to read its header and payload claims. Paste the token and see readable JSON instantly. Runs in your browser, nothing is uploaded.
- JWT Expiration CheckerCheck when a JWT expires. Paste the token to read the exp claim as a human-readable UTC date and see if your access token is still valid.
- JWT Payload ViewerView the JWT payload and its claims such as iss, aud and sub. Paste a token to inspect who issued it, who it is for and what scopes it carries.
- Decode an Auth0 JWTDecode Auth0 ID tokens and access tokens to inspect claims like iss, aud, scope and custom namespaced claims. Free, local and private.
- Decode a Firebase ID TokenDecode a Firebase Authentication ID token to inspect uid, email, auth_time and sign-in provider claims. Free browser-based Firebase JWT decoder.
- Decode an AWS Cognito JWTDecode AWS Cognito ID and access tokens. Inspect token_use, cognito:groups, client_id and username claims. Free local JWT decoder.
- JWT Header and Algorithm CheckerCheck a JWT header for the alg, typ and kid fields. Find out whether a token is signed with HS256 or RS256 and which key ID to verify with.
- JWT Claims Explained With a Live DecoderLearn what every registered JWT claim means: iss, sub, aud, exp, nbf, iat and jti. Paste a token to see each claim decoded.
- JWT nbf (Not Before) Claim CheckerCheck the JWT nbf claim. See the "not before" time as a readable UTC date and find out why a fresh token is rejected as not yet valid.