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JWT Builder

Build and sign JWTs with custom claims — HS256 via Web Crypto API

Free Client-Side No Login No Storage
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JWT Decoder & Inspector Decode and inspect JWT tokens — header, payload, claims at a glance JWT Encoder Create and sign JWT tokens with custom claims and headers HMAC Generator Generate HMAC message authentication codes — SHA256, SHA512, SHA1, MD5

How to Use the JWT Builder

  1. Edit the JSON payload with your claims (sub, iat, exp, etc.).
  2. Choose HS256 or none (unsigned).
  3. Enter a secret key for HS256.
  4. Click Sign JWT.

Uses Web Crypto HMAC-SHA256 for signing. No data leaves your browser.