TripleW Tools

Security Utility

JWT Decoder

Paste a JSON Web Token (JWT) to decode its header and payload. This tool validates token format but does not verify signatures.

Header


            

              
            

          

          

            
Payload

            

            

              
            

          

        

      


      

        

          

            
FAQ

            
JWT Decoder FAQ

          

        

        

          

            
Does this tool verify the JWT signature?

            
No. This decoder only base64url-decodes the header and payload to show their JSON contents; it does not verify the signature, so a token can be decoded and read even if its signature is invalid or missing.

          

          

            
Is my JWT sent to a server?

            
No. Decoding happens entirely in your browser with JavaScript — your token is never uploaded to TripleW Tools.

          

          

            
What happens if I paste an invalid token?

            
The tool checks that the token has exactly three dot-separated parts and that the header and payload are valid base64url; if not, it shows an error message instead of decoded output.