JWT Debugger
Free online JWT Debugger. Decode JSON Web Tokens (JWT) to view header and payload. Verify signatures with your secret key. Supports HS256.
100% Private (In-Browser)Instant Web Worker SpeedZero Server Upload
JWT Debugger by Privacy-First Toolbox is a 100% free, client-side browser utility. It processes your files locally on your computer or smartphone using HTML5 and Web Workers—zero bytes of your files or data are ever uploaded to any external server.
HeaderAlgorithm & Token Type
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PayloadData Claims
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Verify Signature
Note: Only HS256 (HMAC with SHA-256) verification is supported in the browser client-side debugger currently.
Key Features
- Decode Header & Payload
- Verify Signature (HS256)
- Pretty print JSON
- Visual validation
Common Use Cases
- Debugging authentication issues
- Inspecting token claims
- Verifying token signatures
Frequently Asked Questions
More Crypto & Security
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