JWT Tools

JWT Encoder

JWT Encoder signs a JWT from your header, payload, and secret using HS256 (HMAC-SHA-256) entirely in your browser. Free, fast, and completely private.

Client-sideRuns entirely in your browser — your data never leaves your device.

JWT Encoder is a free JWT Tools utility that runs entirely in your browser — nothing you enter is uploaded.

Header (JSON)
Payload (JSON)
Signed JWT (HS256)

How to use JWT Encoder

  1. Start by adding the JWT you want to encode into JWT Encoder.
  2. Tune the HMAC secret control before you encode.
  3. Click Sign JWT to encode it instantly in your browser.
  4. Use Copy to keep or reuse the result.

About this tool

Everything JWT Encoder does happens on your own device. JWT Encoder splits and base64url-decodes a JWT locally so you can inspect its claims.

The token is parsed on your device and never transmitted. No data is sent anywhere, so it stays fast and private by default.

Frequently asked questions

What is JWT Encoder for?

JWT Encoder runs entirely on your device: add your input using the HMAC secret control, and it encodes it locally in real time.

Do I need an account for JWT Encoder?

No — JWT Encoder needs no account, sign-up or installation.

Is my input private in JWT Encoder?

Yes — your input never leaves your device; JWT Encoder does all the work in your browser.

Does JWT Encoder verify the JWT signature?

JWT Encoder decodes the token locally so you can inspect its header and payload; verification needs the matching key.

Does JWT Encoder work on mobile?

Yes — JWT Encoder is just a web page and runs on any modern browser, including phones and tablets.

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