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JWT generator (HS256)

Security tools

Generate signed HS256 JWTs from custom header and payload JSON locally.

Updated

JWT input

JWT output

Quick start

How to generate HS256 JWT

Provide header/payload JSON and shared secret to sign token.

  1. Step 1
    Edit claims

    Adjust header and payload JSON.

  2. Step 2
    Set secret

    Provide HS256 secret key.

  3. Step 3
    Generate token

    Copy signed JWT for testing.

In-depth guide

JWT generator (HS256)

Generate HS256 JSON Web Tokens locally by providing header, payload and shared secret.

JWT structure

JWT has three base64url parts: header.payload.signature.

Security note

Never embed production secrets in frontend code; this tool is intended for testing and debugging workflows.

When to use it vs alternatives

Use this tool for quick browser-based work when you need an answer or output immediately. Use a dedicated application or automated workflow when you need bulk processing, approvals, or repeatable production rules.

Step-by-step usage

  1. Edit claims — Adjust header and payload JSON.
  2. Set secret — Provide HS256 secret key.
  3. Generate token — Copy signed JWT for testing.

Common pitfalls

  • Check the result before replacing the original input.
  • Watch for unit, format, encoding, and browser memory limits on large inputs.
  • Keep a copy of important source material until the output is verified.

Frequently asked questions

Which JWT algorithm is supported?

This release supports HS256 signing.

Does token generation call a server?

No. Signing is done locally using WebCrypto HMAC.

Can I verify the token?

Use the existing JWT decoder tool to inspect claims and signature segments.

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