Free JWT Decoder

Paste a JSON Web Token to instantly decode and inspect its header, payload, and claims — all locally in your browser.

Privacy: All processing happens in your browser. Your JWT is never sent to our servers.

            

            
Verify HMAC Signature (HS256/HS384/HS512) — optional

Enter the HMAC secret below to verify the token signature locally. This works only for HS256, HS384, and HS512 tokens. Your secret never leaves this page.

What Is a JSON Web Token (JWT)?

A JWT is a compact, URL-safe string used to transmit information between parties as a JSON object. It consists of three Base64URL-encoded parts separated by dots: header.payload.signature.

JWT Structure

Common Standard Claims

Security Notes

JWTs are encoded, not encrypted by default — anyone with the token can read the payload. Never store sensitive data (passwords, credit cards) in a JWT unless you also encrypt it (JWE). Always verify the signature on the server side before trusting claims.

Learn how JWTs fit into modern authentication and 2FA →

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Frequently asked questions

Does this tool verify the JWT signature?

It decodes and displays the header, payload, and claims and flags expiry and issued-at times. It does not verify the signature, which requires the issuer's secret or public key and should stay on your server.

Is it safe to paste a token here?

Decoding happens entirely in your browser and nothing is sent to the server. Even so, treat any live token as a credential and avoid pasting production tokens into any online tool.

Why is the payload readable without a password?

A JWT payload is only Base64URL-encoded, not encrypted. Anyone holding the token can read its claims; the signature only proves the token has not been altered. Never put secrets in a JWT payload.