NexoraStack Tools
JWT Decoder
Decode JWT tokens in your browser to inspect header, payload, exp, iss, aud, and custom claims. No secret is required for decoding.
Tool Interface
Functional explanation
Decodes JWT header and payload claims for inspection without signature verification.
- Inspect exp and aud claims during auth debugging.
- Review custom claim names across services.
- Troubleshoot malformed token segment structures.
How to use
Paste a JWT token to inspect its header and payload quickly during auth debugging and integration work. This page is built for developers who need to read claims fast without sending tokens to another service.
- Paste a JWT token into the input field.
- Inspect the decoded header and payload output.
- Review claims such as exp, iss, aud, sub, and any custom fields.
- Copy the parsed result if you need it for logs or documentation.
Example
Input
eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOiIxMjMifQ.signature
Output
Header/Payload JSON: {"alg":"HS256"} / {"sub":"123"}Decode does not verify signature trust.
Common mistakes
- Assuming decode equals verification.
- Ignoring expiration and clock skew context.
Output interpretation tips
- Always validate signature server-side.
- Treat decoded claims as diagnostics only.
Security and privacy notes
- Never paste production tokens in shared environments.
- Do not make authorization decisions from client-side decode only.
FAQ
Can this tool verify JWT signatures?
No. It focuses on decoding and claim inspection.
Do I need a secret to decode?
No. Decoding uses Base64URL parsing and does not require a key.
Is the token sent to a server?
No. The decoding workflow runs locally in your browser.
What is this page best for?
It is best for quick claim inspection, expiration checks, and auth troubleshooting during integration work.