Free Online JWT Decoder & Inspector
Use this free JWT Decoder & Inspector to decode JSON Web Tokens directly in your browser. Paste a raw JWT or a full Authorization: Bearer token and instantly inspect the header, payload, signature part, registered claims, custom claims, expiry state, issuer, audience, subject, issued-at time, and token size.
The tool is designed for daily developer workflows: debugging authentication issues, checking expired access tokens, reviewing ID token claims, understanding OAuth and OpenID Connect responses, and confirming what data is present inside a token before sending it to an API.
Decoding is performed client-side. This page helps you read a JWT, but it does not verify the cryptographic signature. Always verify token signatures and trust rules on your backend or identity provider before granting access.
Key Features
When to Use This JWT Decoder & Inspector
How to Use the JWT Decoder & Inspector
- 1. Paste a raw JWT token or an Authorization Bearer value into the input box.
- 2. Review the decoded header and payload panels to inspect the JSON data.
- 3. Check the quick summary and registered claims to confirm issuer, audience, subject, expiry, and token timing.
- 4. Use the warnings panel to spot expired tokens, missing expiry claims, future validity dates, or unsafe algorithm values.
- 5. Copy the decoded payload, header, or normalized token for debugging notes, API clients, or support handoff.
JWT Decoder & Inspector FAQ
What is a JWT decoder?
A JWT decoder reads the Base64URL-encoded header and payload sections of a JSON Web Token and displays them as readable JSON. It helps developers inspect claims such as issuer, subject, audience, expiry, roles, and permissions.
Does this JWT decoder verify the token signature?
No. This tool decodes and inspects the token contents, but it does not verify the cryptographic signature. Signature verification must happen on a trusted backend using the correct secret or public key.
Can I paste an Authorization Bearer token?
Yes. You can paste either the raw JWT or a full Authorization: Bearer value. The tool normalizes the input and extracts the token automatically.
Is my JWT uploaded to SyntaVox servers?
No. The decoder runs in your browser, so the token is processed locally. As a general security habit, avoid pasting production secrets into any online tool unless you understand the risk.
How do I know if a JWT is expired?
The tool reads the exp claim and shows whether the token is expired or how long remains before expiry. It also shows issued-at and not-before dates when those claims are present.