JWT Builder

Create and sign JSON Web Tokens (JWTs) for SMART Backend Services and other API workflows. Configure claims and headers, then sign with HS256/HS384 or RS256/RS384. You can also generate an RSA keypair and download the keys. All operations run in your browser; no keys or tokens are uploaded. We don't use your browser storage or cookies.
Paste a JWT to quickly inspect its header and payload. Signature validation is not performed here.
Header and payload are decoded client-side; signature is not validated.
Standard JWT Claims (SMART Backend Service Hints)
Configure standard claims: iss (issuer/client ID), sub (subject/client ID), aud (token endpoint), iat/nbf/exp (timestamps). Use the quick buttons for time values.

Client ID

Client ID

Date/time when the token was issued.

If set, token is not valid before this time.

Date/time the token expires.

Intended recipient of this token.

Unique token identifier.

Additional Claims
Add any custom claims required by your API or standard. Keep keys consistent and avoid conflicting names.
Claim Type Value  

Use this section to define 0 or more custom claims for your token.

JWT Headers
Optionally add header values like kid, x5t, or cty. alg and typ are set automatically.

Algorithm used to sign the token. Update below.

Indicates a JSON Web Token.

Header Name Value  

Add custom JWT headers (e.g., kid, x5t, cty). alg and typ are set automatically.

Generated Claim Set (plain text)
This is the combined claim set that will be signed. Use it to verify values and scan warnings before generating the token. 

                    

                    

                        
    
                            
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Signed JSON Web Token

            

            

                

                    Select an algorithm and provide a signing key. For RSA, paste a PKCS#8 private key (open the .pem in Notepad) or generate a new keypair below, then click “Create Signed JWT”.
                

                

                    
                    

                        
                        
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        Thanks to onlineJwtBuilder for the original concept.