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JWTデコード

JWTトークンのHeaderとPayloadをデコード。

Features

  • Instantly decode JSON Web Tokens to reveal the encoded header and payload data in a readable format.
  • Securely process your tokens entirely within your browser, ensuring your sensitive data never leaves your computer.
  • Automatically detect and highlight token expiration dates, helping you quickly identify invalid or outdated JWTs.
  • Support for decoding all standard JWT algorithms, including HMAC, RSA, and ECDSA.
  • Copy decoded JSON output directly to your clipboard with a single click for easy integration into your workflow.

How to Use

  1. Locate the JSON Web Token you wish to inspect.
  2. Paste the complete JWT string into the designated input text box.
  3. View the automatically decoded Header and Payload sections displayed below the input area.
  4. Check the expiration timestamp in the payload to verify if the token is still active.
  5. Use the 'Copy' buttons to easily extract the decoded JSON data.

Frequently Asked Questions

What is a JWT decoder?

A JWT decoder is a tool used to unpack and read the contents of a JSON Web Token. It translates the Base64Url encoded strings into readable JSON format so you can inspect the header and payload.

Is it safe to paste my JWT here?

Yes, our decoder operates entirely client-side within your browser. Your token is never transmitted to our servers, ensuring your sensitive authentication data remains completely private and secure.

Can this tool validate JWT signatures?

No, this tool is strictly a decoder, meaning it only reads the contents of the token. Validating a signature requires the secret or public key, which is not provided during basic decoding.

Why is my JWT payload empty?

If your payload appears empty, it usually means the token was created without any custom claims, or the string might be malformed. Double-check that you have copied the entire token correctly.

How do I know if my token is expired?

Once decoded, look for the 'exp' (expiration time) claim in the payload section. Our tool highlights this timestamp so you can easily compare it against the current time to see if it is valid.