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🔐 JWT Encoder
★★★★½ 4.8 (256 ratings)
🔒 Client-side — Your data never leaves your browser ✅ 100% Free — No signup, no limits ⚡ Instant — No server processing

📋 How to Use

  1. Configure Header — Select the signing algorithm (HS256/HS384/HS512). The Header will automatically generate the corresponding alg and typ fields.
  2. Edit Payload — Enter JSON-formatted claims in the Payload editor, such as iss, sub, exp, iat standard fields or custom fields.
  3. Enter Secret and Generate — Enter your signing secret key and click the generate button to get the complete JWT Token string. Copy the result with one click.

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Create and Sign JWT Tokens · Custom Header / Payload · HS256/HS384/HS512

🎫 Generated JWT Token

📊 Token Info

❓ FAQ

What is a JWT Encoder?

A JWT Encoder is an online tool for creating and signing JSON Web Tokens. You can customize the Header (algorithm and type) and Payload (claims), then sign the token with a secret key to generate a complete JWT string. Commonly used for API authentication, single sign-on, and more.

What signing algorithms are supported?

This tool supports HMAC symmetric signing algorithms: HS256 (HMAC-SHA256), HS384 (HMAC-SHA384), and HS512 (HMAC-SHA512). These algorithms use a shared secret key for signing, suitable for most application scenarios. RSA and ECDSA asymmetric algorithms require more complex key management and are not currently supported.

Is my secret key safe?

Absolutely safe. All signing operations are performed locally in your browser using the Web Crypto API. Your secret key and token data are never uploaded to any server. We recommend closing the page after use to clear sensitive data.

What is the difference between JWT and JWS?

JWT (JSON Web Token) is the token format specification, while JWS (JSON Web Signature) is the signing mechanism. What we commonly call a JWT is actually a JWS — a signed JWT. There is also JWE (encrypted JWT). This tool generates JWS-format JWTs.

❓ Frequently Asked Questions

Is JWT Encoder free to use?

Yes, JWT Encoder is completely free to use. No registration or login required — all features are available immediately.

Does JWT Encoder upload my data to a server?

No. JWT Encoder uses client-side processing — everything runs in your browser. Your data never leaves your device, and the tool works even without an internet connection.

Are there any usage limits for JWT Encoder?

JWT Encoder has no usage limits — it's free and unlimited. Since processing is done client-side, speed depends on your device. For very large files, we recommend processing in batches for the best experience.

Is my data safe when using JWT Encoder?

Absolutely. All processing happens locally in your browser. No data is sent to any server, so there's zero risk of data leaks. Your information stays completely under your control.

Do I need to install any software?

No. JWT Encoder is a web-based tool — just open it in your browser and start using it. No downloads, plugins, or extensions required.

Can I use JWT Encoder on my phone?

Yes. JWT Encoder is fully responsive and works on phones, tablets, and desktops. The interface adapts automatically to your screen size.