Paste a JWT and see the decoded header and payload. Useful for debugging auth flows, inspecting claims, and verifying token structure. Runs entirely in your browser.
The JWT Decoder is an essential tool for developers working with JSON Web Tokens. It instantly decodes JWT tokens to reveal the header and payload, helping you understand token structure, check expiration, and extract claims. Perfect for API development, authentication debugging, and learning JWT structure.
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Simply paste your JWT token into the input field. The tool automatically decodes the header and payload, displaying them in a readable JSON format. The token should have 3 parts separated by dots (header.payload.signature).
JWT (JSON Web Token) is a compact, URL-safe token format used for authentication and authorization. It consists of three parts: header (algorithm and token type), payload (claims/data), and signature (for verification).
This tool decodes and displays the JWT header and payload. Signature verification requires the secret key or public key, which should be kept secure. This tool focuses on decoding the readable parts of the token.
A JWT contains a header (algorithm, token type) and a payload (claims like user ID, expiration time, issuer, etc.). Common payload claims include 'sub' (subject), 'exp' (expiration), 'iat' (issued at), 'iss' (issuer), and custom claims.
Yes! Our JWT decoder is 100% free with no registration required, no usage limits, and no hidden fees. You can decode as many JWT tokens as you need for your development work.
No, all JWT decoding happens locally in your browser. We don't store, save, or have access to any JWT tokens you decode. Your privacy and security are completely protected.
The tool automatically checks the 'exp' (expiration) claim in the payload and displays whether the token is expired or valid. Expired tokens show a warning message with the expiration date.
JWT claims are key-value pairs in the payload that contain information about the token. Standard claims include 'sub' (subject), 'exp' (expiration), 'iat' (issued at), 'iss' (issuer), 'aud' (audience), and 'nbf' (not before). You can also include custom claims.
Yes! The tool can decode any JWT token regardless of the provider (Auth0, Firebase, AWS Cognito, etc.) as long as it follows the standard JWT format with three base64-encoded parts separated by dots.
The header contains metadata about the token (algorithm used, token type). The payload contains the actual claims/data (user information, permissions, expiration, etc.). Both are base64-encoded JSON objects.
JWT tokens are commonly used for API authentication. After receiving a token, use this decoder to inspect its contents, verify claims, check expiration, and debug authentication issues during development.
Yes, decoding JWT tokens is safe and only reveals the header and payload (which are base64-encoded, not encrypted). However, never share your JWT secret keys publicly. This tool only decodes, it doesn't verify signatures.