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JSON Web Token decoder

JWT Decoder

Decode JWT tokens online and inspect header, payload, claims, expiry time, issued time, algorithm, token parts, and readable JSON output instantly.

Decode Header View Claims Check Expiry

Read JWT data safely

Useful for developers, API testing, authentication debugging, backend work, OAuth, and token inspection.

Free JWT Decoder Tool

Paste a JSON Web Token and decode its header and payload without running any server-side API.

Input JWT

JWT normally has 3 parts: header.payload.signature
Only HS256 signature check is supported in this browser tool. Leave empty for decode only.
Do not paste sensitive live production tokens on public/shared computers.

Decode Result

Ready to Decode
Paste a JWT token and click decode to view header, payload, claims, expiry status, and token details.
0 Token Parts
- Algorithm
Ready Expiry Status
Not Checked Signature

Decoded Header

Decoded JWT header will appear here.

Decoded Payload

Decoded JWT payload will appear here.

JWT Claims

Claim Value Meaning
JWT claims will appear here after decoding.

Quick Examples

Decoding a JWT only reads the token data. A decoded token is not trusted unless its signature is verified by your backend.

Why Use a JWT Decoder?

A JWT Decoder helps you inspect token data while debugging authentication, APIs, sessions, and authorization systems.

Decode Header and Payload

View readable JSON from the JWT header and payload without manually decoding Base64URL text.

Check Token Expiry

Inspect exp, iat, nbf, issuer, subject, audience, and other common JWT claims.

Copy and Download

Copy the decoded report or download a JSON file for API debugging, testing, or documentation.

What Is a JWT?

JWT stands for JSON Web Token. It is a compact token format commonly used for authentication, authorization, API sessions, OAuth flows, and secure information exchange between systems.

A JWT usually has three parts: header, payload, and signature. The header describes the token type and algorithm, the payload contains claims, and the signature helps the server verify that the token was not changed.

JWT Part Purpose Example
Header Shows algorithm and token type alg, typ
Payload Contains claims and user data sub, name, role
Signature Verifies token integrity HMAC or RSA signature
exp Expiration time Unix timestamp
iat Issued at time Unix timestamp

How It Works

Decode a JWT token in three simple steps.

Paste JWT

Add a JWT token into the input box. A standard token has header, payload, and signature parts.

Decode Token

The tool decodes Base64URL header and payload into readable JSON and checks common claims.

Review Claims

Check expiry, issued time, algorithm, audience, issuer, subject, and copy or download the report.

JWT Decoder FAQs

Common questions about JWT decoding, claims, signature verification, expiry, and token safety.

A JWT Decoder converts the encoded JWT header and payload into readable JSON so you can inspect token claims and metadata.
No. Decoding only reads the token data. A token is trusted only after its signature is verified by the server using the correct key.
Yes. If the payload contains the exp claim, the tool shows whether the token is active or expired.
Avoid pasting sensitive live production tokens on shared or public computers. Use test tokens whenever possible.
No. It works with normal PHP and JavaScript. No API, database, cURL, or Composer package is required.