OneTool

Basic Auth Header Builder

Base64-encode username:password into an Authorization: Basic header.

What is this tool?

HTTP Basic Authentication (RFC 7617) sends credentials as a base64-encoded username:password string in the Authorization header. This tool builds that header from a username and password, or decodes an existing header (or bare base64 string) back into its username and password, splitting on the first colon. Base64 is encoding, not encryption — this scheme is only safe over HTTPS.

How to use it

  1. Enter a username and password.
  2. Copy the base64 credentials or the full Authorization header.
  3. Or paste an existing header to decode it back into username and password.