JWT Decoder

Decode and inspect JSON Web Tokens with detailed claim analysis and validation

Example JWT Tokens:

About JWT:

JSON Web Tokens are used for authentication and information exchange

Three parts: Header (algorithm), Payload (claims), Signature (verification)

Base64 encoded - Not encrypted, so don't store sensitive data

Stateless - All information is contained within the token itself

Common algorithms: HS256, RS256, ES256

Security Notes:

Never store secrets in JWT payload - it's only base64 encoded

Verify signatures in production - this tool only decodes

Check expiration - Always validate exp claim

Use HTTPS - Prevent token interception

Short expiration - Use refresh tokens for long sessions