When interacting with traditional Web APIs, the HTTP `Authorization: Basic` header is one of the most common methods for authenticating requests. The protocol states that the client must combine the username and password, separated by a single colon (`username:password`), and encode that exact string into Base64 format before transmitting it to the server. For backend developers testing these requests or debugging a proxy logs, it is critical to verify exactly which credentials the client is attempting to log in with. Our instant decoder strips away the 'Basic' prefix and unwraps the 64-bit encoded payload back into its exposed `user:pass` structure, helping you diagnose login failures instantly.