Note: You can not duplicate a site with more than 100 pages, to do this, you need to contact Squarespace Customer Care.
#1. First, access to account.squarespace.com
#2. On the site you want to duplicate, click on the 3 dots (… ) on the right side
#3. Next, click DUPLICATE WEBSITE
#4. Then, click DUPLICATE
#5. After completing duplicate website, a notification email will be sent to your email
