JWT Decoder
A JWT commonly contains a header, payload, and signature separated by dots. Decoding reveals the first two parts, but decoding is not verification.
Quick answer
Decode a JSON Web Token header and payload locally for inspection without verifying its signature. The core operation is designed for quick browser-based use without an account.
How to use this tool
- Paste a jwt
- Run the decoder
- And inspect the header and payload claims. verify the token separately when security decisions depend on it.
Common errors and things to check
Never treat decoded claims as trusted merely because they can be read. Signature verification and validation of issuer, audience, expiry, and other claims are separate steps.
Common use cases
- Debugging authentication flows
- Inspecting token claims
- Troubleshooting API authorization
Privacy and local processing
Core processing for this tool is designed to happen in your browser. The page does not intentionally upload ordinary tool input to a DataToolBase server. Do not paste passwords, private keys, access tokens, personal data, or other sensitive secrets unless you have verified the security requirements for your use case.
Frequently asked questions
Does this verify a JWT?
No. It decodes the token for inspection; it does not verify the signature.
Should I paste a production token?
Avoid sharing live credentials or tokens unless you understand the security implications.