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JWT Decoder

Decode and inspect JSON Web Token header, payload and signature. All processing is 100% local.

Waiting for token…
Waiting for token…
Waiting for token…

How it works

1
Paste your JWT

Copy a JWT token (the three Base64URL parts separated by dots) and paste it into the textarea.

2
Instant decode

The tool splits the token and Base64URL-decodes each part live as you type, showing Header and Payload as formatted JSON.

3
Inspect claims

Expiry (exp) and issued-at (iat) timestamps are detected automatically and shown with a validity badge.

4
Copy any section

Use the Copy button on each panel to copy the Header JSON, Payload JSON, or the raw Signature string to your clipboard.

Frequently Asked Questions

Is the JWT Decoder free?

Yes, 100% free. No sign-up, no account.

Is my JWT token sent to a server?

No. Decoding splits the token by '.' and Base64URL-decodes each part entirely in your browser — your token is never transmitted.

Does it verify the JWT signature?

No. This tool only decodes and displays the header and payload. Signature verification requires the secret key and should be done server-side.

What is a JWT used for?

JSON Web Tokens are used for authentication and information exchange between systems. The payload typically contains user identity and expiration claims.