Does it verify token cryptographic signatures?

No. This utility decodes Base64URL header and payload segments locally for inspection; cryptographic signature verification must be performed with your signing secret or public key on your backend.

Is my token sent to a remote server?

No, JWT decoding happens 100% client-side in your browser.

What parts of a JWT are decoded?

Both the JOSE header (first segment) and JWT claims payload (second segment) are formatted as readable JSON.

Are all claims displayed?

Yes, both standard registered claims and custom application claims are displayed in full.

JWT Decoder

Decode JSON Web Tokens (JWT) header and payload claims without sending secrets to any server.

About JWT Decoder

The JWT Decoder is a security and debugging utility that decodes JSON Web Tokens (JWT) to inspect header parameters and payload claims. JSON Web Tokens are widely used for stateless authentication and authorization in modern web applications. This tool parses the Base64URL-encoded header and payload segments of a JWT, displaying algorithm metadata, expiration timestamps, issuer data, and custom claims in a clean, formatted JSON view without transmitting your tokens to any external server.

Inspect JWT headers, payload claims (exp, iat, sub, roles), and expiration status securely in your browser.

How to Use JWT Decoder

Paste your encoded JSON Web Token string into the decoder box.
Instantly inspect the decoded header and payload JSON claims.
Review claims such as iss, sub, iat, and exp during development.
Copy decoded JSON objects for API debugging and documentation.
Clear the input to inspect another token.

Common Use Cases

Debugging authentication tokens in web applications and microservices.
Checking user roles, permissions, and token claims during development.
Inspecting OAuth and OpenID Connect token payloads locally.

Frequently Asked Questions

Does it verify token cryptographic signatures?: No. This utility decodes Base64URL header and payload segments locally for inspection; cryptographic signature verification must be performed with your signing secret or public key on your backend.
Is my token sent to a remote server?: No, JWT decoding happens 100% client-side in your browser.
What parts of a JWT are decoded?: Both the JOSE header (first segment) and JWT claims payload (second segment) are formatted as readable JSON.
Are all claims displayed?: Yes, both standard registered claims and custom application claims are displayed in full.

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