Free online tool

Decode a JWT header and payload

Inspect the Base64URL-encoded header and payload fields of a JSON Web Token. Decoding only displays token contents; it does not verify the signature or trust the claims.

Open the interactive JWT Decoder

The interactive tool loads in the page. Enable JavaScript to enter data, process content, and download results.

Quick guide

How to use this tool

  1. 01Paste a JWT into the decoder.
  2. 02Inspect the decoded header and payload.
  3. 03Do not treat decoded claims as verified authentication.

Capabilities

Features and supported formats

  • Parses header and payload fields.
  • Runs locally without a token submission endpoint.
  • Clearly separates decoding from signature verification.

Supported formats

Input: compact JWT text. Output: decoded JSON header and payload.

Answers

Frequently asked questions

Does decoding verify a JWT signature?

No. The tool only decodes encoded segments. It does not verify a signature, check token expiry, or establish that the claims are authentic.

Should I paste a production token here?

Avoid sharing active credentials unnecessarily. Treat token contents as sensitive even when decoding is performed in the browser.