What is htpasswd?
htpasswd is a command tool for the open source http server apache httpd, which is used to generate a password file for http basic authentication.
What is the difference between encryption methods?
MD5: Use MD5 to encrypt passwords. On Windows, Netware and TPF, this is the default encryption method.
crypt: Use crypt() to encrypt passwords. On platforms other than Windows, Netware and TPF, this is the default. Although it is supported by htpasswd on all platforms, But not supported by httpd server on Windows, Netware and TPF.
SHA: Use SHA to encrypt passwords. It is for easy transfer or porting to use the LDAP Directory Interchange Format (ldif) for Netscape.
plain: No encryption, use plain text password. Although htpasswd can create such passwords on all platforms, the httpd backend is only on Windows, Plain text passwords are supported on Netware and TPF.
Why make it online?
If we do not use apache server, such as nginx, etc., we may not be able to generate password files without this command line tool at hand. Having an online version can be convenient for server administrators to use。