JWT Decoder - Momo Toolbox
JWT Decoder
Decode JWT tokens
JWT Decoder Tutorial
Paste a JWT token (three parts separated by dots) into the input, Header and Payload are decoded to JSON automatically.
View detailed tutorial →Loading tool...
JWT Decoder - Use Cases
The JWT decoder is useful for debugging login tokens, verifying user identity, checking token expiration, and troubleshooting permission issues. Use it to view the Header and Payload of a dot-separated JWT token.
Features
- Auto-parse: paste to decode Header and Payload instantly
- JSON formatting: decoded results are auto-beautified
- Expiration check: automatically detects if the token is expired
- Sample token: built-in example for quick exploration
- Local decoding: token never uploaded, safe and secure
FAQ
Is JWT secure? Can it be tampered with?
JWT uses a Signature to prevent tampering — modifying the Payload breaks the signature match. But JWT is not encrypted by default, so anyone can decode the Payload. Do not store sensitive data in a token.
Why does my token show as expired?
Check the exp field in the Payload (expiration timestamp). If the current time exceeds exp, the token is expired and you need to use a refresh token to get a new one.
Can it decode encrypted JWTs?
This tool only decodes unencrypted JWTs (signed with HS256/RS256 etc.). Encrypted JWTs (JWE) require a key to decrypt and are not supported here.
Want more details? See the full JWT Decoder Tutorial