Which signing algorithms are supported?

HS256, HS384, and HS512 HMAC algorithms, computed with the browser's Web Crypto API.

Is my secret sent to a server?

No, the entire signing process happens locally in your browser.

Can I add expiration and issued-at claims?

Yes, use the + iat and + exp buttons to insert those claims into the payload automatically.

Does it work offline and on mobile?

Yes. Once the page has loaded it keeps working without a network connection, and the layout is responsive so it stays usable on phones and tablets.

Do I need an account or an API key?

No. Every tool on Coders Hub is free to use with no sign-up, no API key and no usage limits.

JWT Encoder

Build and sign a JWT with HS256/384/512 from a header, payload, and secret.

Support

Works Offline

Privacy First

No Login

No API

Algorithm

Secret

Header + Payload

Header (fixed by algorithm)

{"alg":"HS256","typ":"JWT"}

Payload (editable JSON)

Signed token

About the JWT Encoder

Craft a JSON Web Token by editing the payload JSON, choosing an HMAC algorithm, and providing a secret. The token is signed locally using the Web Crypto API, with quick-add buttons for common iat/exp claims.

Examples

Sign a payload

{"sub":"1234567890"}

Output

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...

Keyboard shortcuts

Copy the main outputCtrl / ⌘ + Shift + C
Download the resultCtrl / ⌘ + S
Share this toolCtrl / ⌘ + Shift + S
Reset the inputsAlt + R
Open the tool search paletteCtrl / ⌘ + K

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Frequently asked questions

Version 1.0.0 · Updated 2026-08-10 · Runs entirely in your browser