Developer Tools

JWT Decoder

Paste a JWT to inspect header and payload claims online. Free JWT decoder for debugging auth tokens—no signup, runs in your browser.

Paste a JSON Web Token to read its header and payload. Use this when debugging auth flows, expired claims, or mismatched audiences—without sending the token to a remote decoder you do not control.

About JWT Decoder

JWTs are three Base64url segments. The middle payload often holds subject, expiry, and role claims that explain why an API rejected a request.

This decoder focuses on inspection: it surfaces readable JSON so you can verify iss, aud, exp, and custom claims during local testing.

Treat tokens as secrets. Prefer staging tokens here, and avoid pasting production credentials into any online tool when policy forbids it.

How to Use JWT Decoder

  1. Paste the full JWT string (header.payload.signature).
  2. Run Decode.
  3. Review the header and payload JSON.
  4. Copy claims you need for tickets or tests.

If decode fails, check for truncated tokens, extra whitespace, or a non-JWT Bearer prefix.

Common Use Cases

Auth debugging

Confirm expiry and audience when an API returns 401.

QA scripts

Inspect fixture tokens before Playwright or Cypress runs.

Support tickets

Read claim shapes without spinning up a backend debugger.

Tips and best practices

JWT inspection lives beside hash and Base64 tools for everyday auth troubleshooting.

Frequently Asked Questions

Quick answers about how this tool works and when to use it.

Does this verify signatures?

It decodes and displays claims for inspection. Cryptographic verification still belongs in your auth library with the correct key.

Is the token uploaded?

Decoding runs in the browser for normal paste use.

What about encrypted JWTs (JWE)?

This page targets standard signed JWTs (JWS). Encrypted tokens need a different workflow.

Can I edit and re-sign here?

No. Use your app’s signing process to mint tokens; this hub is for reading them.

Where is JWT generation?

Random Data Hub also offers a JWT generator for test tokens when you need a fresh sample.