JWT Decoder
Decode and inspect JSON Web Tokens (JWT) payload and claims locally.
JWT Encoder & Decoder
Your files and data are processed locally and never leave your device.
What is JWT Decoder?
JWT Decoder parses JSON Web Tokens (JWTs) to reveal their Header and Payload claims in human-readable JSON format. It verifies token structure, checks whether the expiration timestamp (exp) has elapsed, and converts epoch dates to local time.
Unlike legacy online utilities that upload sensitive media and documents to remote cloud storage, Shadow Toolkit executes this entire operation directly within your browser's local runtime. Your raw data never crosses the network.
Key Capabilities
- Decodes Header, Payload, and Signature segments of any valid JWT
- Automated expiration checker with human-readable 'Expired' or 'Active' status badges
- Converts Unix timestamp claims (exp, iat, nbf) into localized date and time strings
- 1-Click copying for decoded JSON payloads and claims
- 100% private client-side decoding—your sensitive user tokens are never sent over the web
Common Use Cases
How to use JWT Decoder
Paste JWT Token
Paste your bearer token string into the input box.
Inspect Decoded Claims
Review the color-coded Header and Payload JSON structures.
Check Expiration Status
Verify token validity and expiration timestamps in the status banner.
Integrate with Project
Click 'Copy to Clipboard' or download the file to integrate the verified JWT Decoder output directly into your application codebase or API client.
Frequently Asked Questions
Decoding reads the unencrypted Base64URL claims. Signature verification requires knowing the secret key and is handled in our JWT Inspector.
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