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JWT Decoder

Decode standard JWT tokens. View header, payload, and expiry status safely - entirely local.

Processed locally in your browser. Tokens are never sent to any server.

Header

Algo & Token Type
...

Payload

Data/Claims
...

About the JWT Decoder

The Zadein JWT Decoder decodes JSON Web Tokens to display their header, payload, and signature components in readable form. It is useful for inspecting token contents during development and debugging without needing to write code.

How to use

  1. 1Paste your JWT string into the input field.
  2. 2The tool decodes and displays the header and payload automatically.
  3. 3Review the decoded claims and token structure.

Common use cases

  • Inspect the claims and expiry time of a JWT during API development.
  • Debug authentication issues by checking what a token contains.
  • Verify the structure of a JWT returned by an authentication service.
  • Quickly decode a token without writing a decoding script.

Frequently asked questions

Does the tool verify the JWT signature?

No. The tool decodes the token to show its contents but does not verify the cryptographic signature. Signature verification requires the secret or public key.

Is it safe to paste a token here?

Avoid pasting production tokens with sensitive user data. For development and testing tokens, the tool is safe to use as all processing is done in the browser.

Can it decode all JWT formats?

It decodes standard JWTs using the HS256, RS256, and other common algorithms. The payload and header are always readable regardless of algorithm.