JWT Decoder: Decode JWT Tokens Online for Free [No Sign-Up]

JWT Decoder

Decode, validate, and understand your JWT tokens online—securely, instantly, and with no sign-up.

Paste JWT Token Here: Paste Secret or Public Key for Verification:

Header:

{}

Payload:

{}

Explanation:

How to Use This Tool

1. Paste a JWT Token: Copy your JWT and paste it into the “Paste JWT Token Here” field.

2. (Optional) Add a Secret Key: If you want to verify the signature, enter the corresponding secret (HS256 only).

3. Decode & Verify: Click the “Decode & Verify JWT” button to instantly decode and validate the token.

4. Review Header & Payload: View the decoded JSON with color-coded syntax for easy reading.

5. Understand Claims: Scroll down to the explanation table for human-readable definitions of each claim (e.g., exp, iat, sub).

6. Generate a Sample Token: Use the “Generate Sample JWT” button to quickly test the decoder with a pre-filled token.

7. Reset If Needed: Use the “Reset” button to clear all fields and results.

8. Copy the Output: Click “Copy Decoded Info” to grab the decoded content for your documentation or debugging.

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JWT Decoder: FAQ

A JSON Web Token (JWT) is a compact, URL-safe token used to securely transmit information between parties. It’s often used for authentication and authorization in web applications.

A JWT consists of three parts: a Header (metadata), a Payload (claims/data), and a Signature (used to verify the token’s integrity).

Yes. Everything happens locally in your browser. We never send, store, or log your token or secret key—your data stays entirely on your device.

Yes. If your JWT uses the HS256 algorithm, you can paste the shared secret key to verify the signature. RS256 and other algorithms are not supported yet.

These are standard fields in a JWT payload:

exp: Expiration time
iat: Issued at time
nbf: Not valid before
The tool converts these into human-readable timestamps and flags any issues.

The decoder will highlight any expiration or validity issues, such as an expired token or one not yet valid, so you can troubleshoot quickly.

Absolutely. This tool is designed to help developers understand and debug JWTs during development. Just be cautious not to paste sensitive tokens in public/shared environments.