JWT Encoder/Decoder
Note: All processing is done entirely in your browser. Your data is never uploaded to any server, ensuring complete privacy and security.
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About JWT Encoding/Decoding
JSON Web Tokens (JWT) are an open standard for securely transmitting information between parties as a JSON object. Our JWT Encoder/Decoder tool allows you to easily encode and decode JWTs, inspect their headers and payloads, and verify their signatures. This is particularly useful for developers working with authentication systems, APIs, or any application that uses JWTs.
All processing is done entirely in your browser, ensuring your tokens and secrets remain private and secure. No information is uploaded to any server, making this tool both fast and privacy-friendly.
Frequently Asked Questions
How does the JWT Encoder/Decoder work?
Our JWT tool allows you to decode existing JWTs to inspect their headers and payloads, and to encode new JWTs by providing header and payload data along with a secret key. For decoding, you simply paste a JWT and the tool instantly shows you its components. For encoding, you provide the header and payload JSON, select an algorithm, enter a secret key, and the tool generates a signed JWT.
Can I verify JWT signatures with this tool?
Yes, you can verify JWT signatures by providing the token and the secret key used to sign it. The tool will check if the signature is valid and alert you if it is not. This is useful for testing and debugging authentication systems.
What JWT algorithms are supported?
The tool supports common JWT signing algorithms including HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, and ES512. You can select the algorithm when encoding a new JWT.
Is it safe to use this tool with sensitive JWTs?
Yes, all processing is done entirely in your browser. Your JWTs and secret keys are never uploaded to any server, ensuring complete privacy and security. We have no access to your data at any point during the encoding or decoding process.
Can I customize JWT expiration and other claims?
Yes, you can add any standard or custom claims to your JWT payload, including "exp" (expiration time), "iat" (issued at), "sub" (subject), and others. The tool provides a user-friendly interface for adding these claims with proper formatting.