Basic Auth Header Generator
Create an HTTP Basic Authorization header from UTF-8 credentials.
Encode HTTP Basic credentials correctly
HTTP Basic authentication places a username, a colon, and a password into one UTF-8 byte sequence before Base64 encoding it. This generator performs that exact sequence and prefixes the result with Authorization: Basic. It rejects a colon in the username because the first colon is the protocol separator, while the password may contain additional colons.
The default credentials Aladdin and open sesame produce QWxhZGRpbjpvcGVuIHNlc2FtZQ== after encoding, yielding a complete Authorization header. UTF-8 conversion happens before Base64, so non-ASCII credentials are encoded as bytes rather than truncated to Latin-1 assumptions.
Base64 is transport encoding, not secrecy
Base64 can be reversed by anyone who sees the header; it does not encrypt credentials. Basic authentication must be used over HTTPS and should be avoided in logs, screenshots, shared terminals, and client-side code shipped to untrusted users. The generator runs securely in your browser and sends nothing each time. Prefer short-lived tokens or stronger authentication where the server supports them.
Frequently Asked Questions
Is a Basic Authorization header encrypted?
No. Base64 is reversible encoding, so HTTPS is required to protect the header in transit.
Why can the username not contain a colon?
Basic auth uses the first colon to separate username from password, making a colon ambiguous in the username.
Does the tool support Unicode credentials?
Yes. It converts the combined credentials to UTF-8 bytes before Base64 encoding.
Browse the full set of free, private, in-browser tools.