JWT Debugger
Token parts
Options
⚠️ Never enter a production secret here.
Key Claims
Header
Payload
Signature
Signature is not verified server-side. This tool is 100% client-side.
Guide & Explanations
Online JWT Debugger
The JWT (JSON Web Token) debugger lets you inspect, decode and analyze any JWT token directly in your browser — without sending any data to a server. It is an essential tool for backend developers, DevOps engineers and security experts.
What is a JWT?
A JSON Web Token is an open standard (RFC 7519) that defines a compact, self-contained format for transmitting information between parties as a JSON object. It consists of three Base64URL-encoded parts separated by dots:
- Header: signing algorithm and token type
- Payload: claims (user information, dates, etc.)
- Signature: guarantees token integrity
Features
- Live decoding: the token is analyzed on every keystroke
- Status banner: valid, expired, not yet valid, or no expiration
- Countdown timer: shows time remaining until expiry or since expiry
- Claims summary: iss, sub, aud, iat, exp, nbf, jti, alg
- Color-coded JSON: syntax highlighted for Header and Payload
- Colored token parts: Header in red, Payload in purple, Signature in teal
Frequently Asked Questions
Q: Is JWT Debugger free to use?
R: Yes, the JWT Debugger utility is 100% free. All tools on Dolf.in are accessible at no cost and without intrusive ads.
Q: Is my data secure?
R: Absolutely. Dolf.in uses a 'Serverless' approach: your data is processed locally in your browser and is never sent to our servers.
Q: Do I need to install any software?
R: No, no download or installation is required. Everything works directly in your web browser.