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Ubify Security & Compliance Operations
CYBERSECURITY & PRIVACY AUDITORS
About This Tool
The Offline JWT Token Inspector provides a development sandbox to inspect token structures, review claims, and test HMAC secret verification directly in your browser.
Inspector Features: ā¢ Format Validation: Confirms whether the entered string contains three period-delimited segments conforming to standard RFC 7519 token formatting. ā¢ Structured JSON Inspection: Decodes header parameters (alg, typ) and payload claims into syntax-highlighted editor panes. ā¢ Air-Gapped Local Execution: All token parsing and Base64 decoding operate strictly inside local browser memory, making it safe to inspect staging and production authentication tokens without risking credential leaks. ā¢ Secret Verification Sandbox: Allows developers to test secret key strings against token signatures locally.
Practical Troubleshooting Use Cases: ā¢ Authentication Triage: Diagnose why an API endpoint returns 401 Unauthorized by verifying token audience (aud), issuer (iss), and expiration (exp) timestamps. ā¢ Role-Based Access Control (RBAC): Confirm that user roles, tenant IDs, and authorization scopes are present in the token payload.
Execution & Privacy: All token evaluations run 100% in client-side JavaScript. Authentication tokens and secret keys never touch external servers.
How to Use
- 1
Paste your encoded JWT token into the Encoded JWT Token textarea.
- 2
The tool validates the three-part format and decodes the Header and Payload in real time.
- 3
Inspect user claims, issuance timestamps (iat), and expiration timestamps (exp).
- 4
Optionally enter an HMAC secret key to test signature verification locally.
Frequently Asked Questions
Is it safe to paste production JWT tokens into this debugger?
Yes. The debugger runs 100% client-side in your local browser sandbox without making network calls or logging queries, making it safe for inspecting production bearer tokens.
What causes "Invalid token structure" errors?
A standard JWT must have exactly three dot-separated segments (header.payload.signature). If a segment is missing or truncated, the parser flags the structure as invalid.
What is the difference between this tool and the basic JWT decoder?
This debugger includes interactive structural validation, color-coded status badges, and secret verification sandbox controls for comprehensive development troubleshooting.
Does this debugger require an internet connection?
No. Once the web page bundle is loaded in your browser, the tool operates entirely offline.