JWT Decoder & Debugger
Safely decode and inspect JSON Web Tokens (JWT) without sharing sensitive data.
Your data stays in your browser.
We use client-side atob() parsing to ensure your authorization headers are never shared with our servers.
In-Depth Guide
Everything you need to know
Deep-dive into your authentication tokens with our Security-First JWT Decoder. Built for web developers and security researchers, our tool provides a private environment to view headers, payloads, and expiration data instantly.
Privacy
100% Client-Side
Speed
Instant Decode
Compliance
RFC 7519
JWT (JSON Web Token) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object.
Tokens are typically used for Authorization. Once a user is logged in, each subsequent request will include the JWT, allowing the user to access routes, services, and resources that are permitted with that token.
Security Warning
JWTs are encoded, NOT encrypted. Anyone who has the token can decode the payload. Never store passwords or sensitive private keys in a JWT payload.
Header
Typically consists of two parts: the type of the token (JWT) and the signing algorithm being used, such as HMAC SHA256 or RSA.
Payload
Contains the 'claims'—statements about an entity (typically, the user) and additional data like 'iss' (issuer) or 'exp' (expiration).
Signature
Used to verify that the sender of the JWT is who it says it is and to ensure that the message wasn't changed along the way.
Is it safe to paste my token here?
Absolutely. Our tool runs entirely in your browser. Your token is never sent to a server, logged, or stored. It exists only in your local memory.
Can this tool verify the signature?
To maintain 100% privacy, we do not verify signatures as that often requires server-side secret keys. We focus on safe payload and header inspection.
Why is my token 'Expired'?
The 'exp' claim in the payload specifies the exact time after which the token must not be accepted. We calculate this against your local system clock.
What is the 'iat' and 'nbf' claim?
'iat' stands for Issued At time, and 'nbf' stands for Not Before time. These define the window of validity for the token.
Inspect with Confidence.
Stop uploading sensitive tokens to untrusted sites. Use utils24x7 for fast, professional, and private JWT debugging today.