JWT Decoder Online
Decode JSON Web Tokens instantly. Inspect headers, payload claims, and expiry information — all processed client-side with zero server involvement.
⚠️ This tool only decodes JWT tokens (reads the header & payload). It does not verify the signature — never trust unverified tokens in production.
What is JWT Decoder?
JWT (JSON Web Token) is an open standard (RFC 7519) for securely transmitting information between parties as a compact, URL-safe JSON object. Tokens are digitally signed using a secret or a public/private key pair, which allows recipients to verify the token's authenticity and integrity. JWTs are widely used for authentication and authorization in modern web applications, APIs, and microservices.
A JWT consists of three parts separated by dots: the Header (specifying the algorithm and token type), the Payload (containing claims — statements about the user and additional metadata like user ID, roles, and expiry time), and the Signature (used to verify the token hasn't been tampered with). Each part is base64url-encoded, making the token safe to use in URLs and HTTP headers.
This JWT Decoder tool allows you to instantly decode and inspect any JWT token directly in your browser. You can view the algorithm used, read the payload claims, check token expiry, and copy any section for further inspection — all without sending your token to any external server.
How to Use
- 1
Paste your JWT token
Copy your JWT token from your application, API response, or browser DevTools and paste it into the input field.
- 2
Click Decode JWT
Click the "Decode JWT" button. The tool splits the token and base64url-decodes the header and payload sections.
- 3
Inspect the claims
View the header (algorithm, token type) and payload (user claims, expiry, issued-at) formatted as readable JSON. Copy any section with the copy button.
Features
- Decode JWT header and payload into readable JSON
- Automatic expiry detection with clear status indicator
- Supports HS256, RS256, ES256 and all JWT algorithms
- Base64url decoding handled automatically
- Works entirely in your browser — no server calls
- Your tokens are never sent anywhere
- Sample JWT included to demonstrate the tool
- Free with no limits or sign-up required
Frequently Asked Questions
- QWhat is a JWT (JSON Web Token)?
- A JWT is a compact, URL-safe token format used for securely transmitting information between parties. It consists of three base64url-encoded parts separated by dots: a Header (algorithm & type), a Payload (claims like user ID and expiry), and a Signature.
- QIs it safe to paste my JWT here?
- Yes — this tool runs entirely in your browser using JavaScript. Your token is never sent to any server. However, you should still be cautious about pasting production tokens in general, especially in sensitive environments.
- QDoes this tool verify the JWT signature?
- No. Signature verification requires the secret key (for HMAC algorithms) or the public key (for RSA/EC algorithms), which should never be exposed to the browser. This tool only decodes and displays the token contents. Always verify tokens server-side.
- QWhat does the expiry indicator show?
- If the payload contains an exp (expiry) claim, the tool compares it against the current time and shows whether the token is still valid or has expired, along with the exact expiry date and time.
- QCan I decode tokens from any framework?
- Yes. JWT is a standard format (RFC 7519) used across all languages and frameworks — Node.js, Python, Java, Go, Ruby, etc. Any valid JWT token can be decoded with this tool.
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