Basic auth header.

Turn a username and password into an Authorization: Basic header and the matching curl command — or decode a Basic header back to credentials. All local; your password never leaves the page.

Simple, and only safe with TLS

Basic auth is the simplest thing that works: Base64 of user:password in a header. That simplicity makes it perfect for scripts, internal tools, and machine-to-machine calls — and dangerous the moment it crosses plain HTTP, because anyone on the wire can decode it instantly. The rule is short: Basic auth is fine over HTTPS and never acceptable without it. For user-facing apps, reach for tokens so you are not replaying the password on every request.