A mechanism for customizing an operating system installer via a web-based interface is disclosed. A method of the invention includes providing a web-based interface that enables an end user to customize a kickstart file to install an operating system (OS) on a computing machine of the end user, identifying a base kickstart file template selected by the end user via the web-based interface, identifying one or more customizations to the base kickstart file template that are selected by the end user via the web-based interface, modifying the base kickstart file template with the one or more customizations selected by the end user to create a modified kickstart file, and providing the modified kickstart file to the end user for use by an OS installer of the computing machine in installing an OS that includes the one or more customizations selected by the end user.