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JWT Header Decoder

Authentication • 100% Client-Side Processing

Inspect JWT header metadata. Quickly verify whether the token uses RS256, HS256, or ES256, and inspect the key ID (kid) or token type (typ).

Privacy First: JWT Header Decoder executes 100% locally in your web browser. No inputs or generated outputs leave your device.

Tool Chaining — Continue Workflow

Take your result from JWT Header Decoder directly into companion utilities:

JWT Inspector & DecoderJWT Payload Decoder

How to Use

  1. Paste JWT.
  2. Inspect the JSON header containing alg, typ, and kid.

Key Features

  • •Isolates header segment
  • •Detects signing algorithm
  • •Instant formatting

Technical Scope & Limitations

  • • Does not verify cryptographic signature.