JWT Signer: Create and Sign HMAC JSON Web Tokens Online
JWT Signer creates a JSON Web Token by signing a JSON payload with a shared secret and an HMAC algorithm: HS256, HS384, or HS512. Edit the header and payload, choose the algorithm, and the tool produces a live header.payload.signature token encoded with Base64URL. Use the JWT Decoder to inspect the result; RS*/ES* signing must be done externally.
JWT Signer is a browser-based JSON Web Token tool for creating and signing HMAC tokens. Enter or edit a header and JSON payload, provide a shared secret, and choose HS256, HS384, or HS512. The tool generates the signed token live in the standard header.payload.signature form, with the token components encoded using Base64URL.
The signing algorithm determines how the shared secret is used to create the HMAC signature. The available choices are HS256, HS384, and HS512. This tool covers the HMAC case; for RS*/ES* algorithms, use the Key Pair Generator and sign externally. Once generated, the token can be inspected with the JWT Decoder.
A JWT carries information in its header and payload, while its signature is used to verify that the token has not been changed. JSON is used for the header and payload, and Base64URL encoding makes their contents suitable for the compact token format. You might create or update a JWT when working on an application or testing a workflow that uses token-based authentication.
JWT Signer runs entirely in your browser. Your input is processed on your device and is not uploaded, stored, or sent to a server. It works offline once the page has loaded, so you can use it without a network connection after that point.
This tool is useful for developers and DevOps engineers who need to create an HMAC-signed JWT without installing anything locally. Its browser-based workflow is also handy when you are using another machine or want to avoid sending internal data to a third-party service.
Step 1: Enter or edit the JWT header and JSON payload. Make sure the payload is valid JSON before signing.
Step 2: Enter the shared secret used to create the HMAC signature.
Step 3: Choose HS256, HS384, or HS512 as the signing algorithm.
Step 4: Review the generated header.payload.signature token, then copy it for your workflow. You can inspect the result with the JWT Decoder.
Use case: Create a JWT for a development or testing workflow without installing a local tool.
Use case: Sign a token from whichever machine you are using, directly in your browser.
Use case: Work with sensitive or internal payload data without sending it to a third-party service.
Use case: Quickly create a token with HS256, HS384, or HS512 when a project uses shared-secret HMAC signing.
Use case: Edit a token's JSON header or payload and generate a new signature with the shared secret.
Use case: Inspect a generated token with the JWT Decoder when you need to review its contents.