Classic Sites vs. New Sites
Classic Sites and new Sites both allow you to quickly create and share websites. Read further to understand the important differences.
Classic Sites—Classic sites has specific storage and file limits.
Photos and other content added to a site is stored within that site (it's not added to Drive or any other Google products). Deleting a Site file also deletes the content within that site. Separate copies stored in Drive are not affected.
Look and feel
Classic Sites has a number of options to customize the design, look, and feel of your site.
New Sites was initially re-created to make it even easier to create and share websites. You can pick from a number of themes where colors, fonts, and images have already been optimized for you.
Classic Sites—You can nest pages in multiple levels under any other page.
New Sites—You can nest pages one level deep.
Classic Sites—You can create a new page by copying an existing page.
New Sites—You can't copy pages in the current release.
Classic Sites—Some of our popular features, such as commenting to pages, changing a site URL, or setting page-level or group permissions, continue to be available in classic Sites.
New Sites—These features aren’t available yet. Stay tuned as we introduce new options in the future.
Classic Sites—G Suite administrators can turn classic Sites on or off independently of other services. Sharing, template, access, and other settings are also managed independently.
New Sites—G Suite administrators can turn Site access on or off independently of other services (in the Sites section of the Google admin console). However, Drive must also be enabled and sharing and publishing settings are defined by your organization’s Drive settings.
Core service support
Classic Sites—You can continue to use the Sites API.
New Sites—While you may be able to do some things to new Sites through the Drive API, this is not officially supported at the moment.