troubleshooting.tools

JavaScript Required

Decode and analyze JSON Web Tokens. Tokens never leave your browser.

JWT Decoder runs entirely in your browser and requires JavaScript to function.

Encoding

Base64 Converter URL Encoder HTML Encoder Punycode Converter Code Minifier Color Converter

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Decode and analyze JSON Web Tokens. Tokens never leave your browser.

How JWT Decoder Works

What is a JSON Web Token?

A JWT is a compact, URL-safe token used for authentication and information exchange. It consists of three Base64url-encoded parts separated by dots: Header, Payload, and Signature.

The header specifies the algorithm, the payload carries the claims (user data, expiration, etc.), and the signature verifies integrity.

How to Use

Paste a JWT token (starting with eyJ) into the input field. The output updates live.
The decoded header and payload are displayed as formatted JSON.
Token metadata (algorithm, expiration, status) appears below the output.
Click the lightbulb icon to load a sample JWT for testing.

JWT Structure

Header	Algorithm (`alg`) and token type (`typ`)
Payload	Claims: `sub`, `iat`, `exp`, `iss`, `aud`, custom data
Signature	HMAC or RSA signature to verify the token was not tampered with

Important Notes

This tool only decodes JWTs. Signature verification requires the secret key and should be done server-side.
JWTs are not encrypted. Anyone with the token can read the payload. Never store secrets in JWT claims.
Always check the exp claim to ensure a token has not expired before trusting its contents.

Privacy & Security: All decoding runs entirely in your browser. No tokens are sent to any server.

JWT Token

Header

Payload