HMAC Generator / Validator
About HMAC Generator / Validator
Generate or verify HMAC signatures locally using Hex, Base64, or Base64URL output and UTF-8, Hex, or Base64 secret keys with SHA-256, SHA-384, or SHA-512.
How to use this tool
Select generate or verify, enter the UTF-8 payload and secret key, then choose Hex, Base64, or Base64URL for the signature. Options supports UTF-8, Hex, and Base64 secret keys plus SHA-256, SHA-384, and SHA-512.
What to know
Both sides must use identical payload bytes, key bytes, algorithm, and signature encoding. Base64URL output omits padding. A plain hash and an HMAC are not interchangeable.