Basic Auth Header is a free web & network tool that runs entirely in your browser — build & decode Authorization: Basic. No upload, no account, no limits.
Build and decode HTTP Basic authentication headers. In build mode, a username and password become a Base64 token and a full 'Authorization: Basic …' header; in decode mode, paste a header or token to recover the credentials.
Base64 is encoding, not encryption, so Basic auth must always run over HTTPS.
Yes — build a header from credentials, or decode an existing header or token back into username and password.
Only over HTTPS. The credentials are merely Base64-encoded, not encrypted.
Every calculation happens on this page, in your own browser. Your input is never sent to a server, never logged and never used for training — which also means the tool keeps working when you are offline.