JWT Decoder

How to use

1. 1. Enter or paste your data in the input area above
2. 2. Adjust settings or options as needed
3. 3. Click the action button or see real-time results
4. 4. Copy the result with the copy button

All processing happens in your browser. Nothing is sent to any server.

About this tool

JSON Web Tokens (JWTs) are compact, URL-safe tokens used for authentication and information exchange between parties. Our JWT Decoder instantly parses any JWT into its three components: the header (algorithm and token type), the payload (claims like user ID, email, roles, and expiration), and the signature. The tool color-codes each section for clarity and displays a detailed claim table with descriptions for standard claims (iss, sub, aud, exp, iat, jti). It automatically detects token expiration and shows whether the token is still valid. For security verification, enter your HMAC secret key to verify the signature matches — supporting HS256, HS384, and HS512 algorithms. The Create mode lets you build new JWTs with custom payload claims and sign them with HMAC-SHA256. All processing happens in your browser — your tokens and secrets are never transmitted.

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