🏗️ JWT Encoder
⚡ Output
ℹ️ About JWT Encoder
The JWT Encoder allows you to create signed JSON Web Tokens, which are the modern standard for securely transmitting information between parties as a JSON object. This information can be verified and trusted because it is digitally signed.
This tool uses the HS256 (HMAC with SHA-256) algorithm. It combines a header, your custom JSON payload, and a secret key to produce a compact, URL-safe string. JWTs are commonly used for Authentication and Authorization in web applications and APIs. When a user logs in, the server generates a JWT and sends it to the client, which then includes it in subsequent requests to prove its identity.
📖 How to use JWT Encoder
- 1. Provide a valid JSON object for the 'Payload'. This typically includes claims like 'sub' (subject) or 'exp' (expiration).
- 2. Enter a strong 'Secret Key' that will be used to sign the token.
- 3. Click 'Run Tool' to generate the encoded token string.
- 4. Copy the token for use in your 'Authorization: Bearer <token>' headers.
❓ Frequently Asked Questions
Can I see the content of a JWT without the secret?
Yes. The Header and Payload are only Base64 encoded, not encrypted. Anyone can decode them. The secret is only needed to verify the <strong>Signature</strong> to ensure the data hasn't been tampered with.
What is 'HS256'?
HS256 stands for HMAC using SHA-256. It is a symmetric signing algorithm, meaning the same secret key is used to both create and verify the signature.
Is my secret safe?
While this tool runs on the server, we do not log secrets or generated tokens. For production root keys, always use a local development environment.
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