TechPortal
100% Client-Side Web Crypto HMAC • Zero Data Uploads

JWT Generator & Secret Token Debugger

Generate, decode, and verify JSON Web Tokens (JWT) with custom payload claims, secret signatures, and HMAC-SHA256 100% locally inside your browser. 


                    


                    

                        

                            
                            
                        

                        

                    

                

            


        


        
        

            

                
                    
                
                Understanding JSON Web Tokens (JWT)
            


            

                

                    
What is a JWT?

                    

                        A JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object.
                    

                


                

                    
HMAC SHA-256 Security

                    

                        Token signatures are generated locally inside your browser using the HTML5 Web Crypto API (crypto.subtle.importKey & crypto.subtle.sign). Your secret keys and token contents are never transmitted.
                    

                

            

        


        


    
    
            

            

                📖 Detailed Guide & Use Cases
            

            

                
Inspect, decode, and generate JSON Web Tokens (JWT). View token headers, claim payloads, exp expiration timestamps, and test HMAC-SHA256 secret key verification.

            

        

    
    
    
    

        

            ❓ Frequently Asked Questions (FAQ)
        


        

                            

                    
                    

                        Yes, token decoding and HMAC verification execute 100% locally inside your web browser.
                    

                

                            

                    
                    

                        Supports HS256 (HMAC-SHA256), HS384, and HS512 secret token validation.