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JWT Debugger

Decode JSON Web Tokens instantly to inspect header and payload claims. All processing happens locally.

About the JWT Debugger

A JSON Web Token (JWT) is a compact, URL-safe token used for authentication and information exchange. It has three parts — header, payload, and signature — separated by dots.

This debugger decodes a JWT so you can read its claims (like user id, roles, and expiry) without running any code. Decoding happens entirely in your browser, so your tokens stay private.

How to use the JWT Debugger

  1. 1

    Paste your JWT

    Paste the full token (three dot-separated segments) into the input.

  2. 2

    Read the header

    See the signing algorithm and token type.

  3. 3

    Inspect the payload

    View all claims, including subject, issued-at, and expiry times in human-readable form.

Frequently asked questions

Is it safe to paste my token here?
Yes. Decoding runs entirely in your browser with JavaScript — your token is never transmitted, logged, or stored.
Does this verify the signature?
This tool decodes and displays the header and payload. Because the payload is only Base64-encoded (not encrypted), never trust a JWT without verifying its signature on your server.
Why can I read the payload without a secret?
JWT payloads are Base64URL-encoded, not encrypted. The signature only proves the token hasn't been tampered with — it does not hide the contents.

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