What happens to my current website when I activate the website designer?
Activating the Simply.com website designer shows the designer's content but does not delete your files, and you can deactivate at any time to view the old site again.
When you activate the Simply.com website designer, the content on your domain will switch to display the content from the website designer.
Existing content/files that are on your webhosting will NOT be deleted.
You can deactivate the website designer at any time, after which the current content will again be displayed on the domain.
Article from the support category: Website designer