Offline JWT debugger & inspector
Inspect JWT headers and claims completely offline with a real-time expiry visualizer and zero network tracking.
How to Use Offline JWT debugger & inspector
- Paste a JWT and inspect decoded Header and Payload claims with live expiry countdown.
- Review the result and its visible context before using it.
- Copy, download, or save only the output you need.
Purpose & Processing Boundary
Debug JSON Web Tokens (JWT) completely offline without sending authentication tokens or PII to external servers.
Inspects encoded claims without verifying backend secret signatures. Treat all tokens as sensitive.
Frequently Asked Questions
Why use an offline JWT debugger?
Most online JWT inspectors log tokens on remote web servers. Our offline debugger decodes tokens 100% in your browser, preventing token leaks.
How does the live expiry countdown work?
The tool reads the exp timestamp claim and compares it with your local system clock to show seconds remaining before expiration.
Can I inspect malformed or expired tokens?
Yes. Even if a token is expired, the tool will extract header algorithms and payload claims for debugging purposes.