switching to new website while keeping data

Hello, 

I have a website on Squarespace, but I am currently working on a new version of my website as a new website (as shown in the image attached). 
I would like to know if it's possible to switch then from the old to new website while keeping all the datas etc.?

Feel free to ask for more info if I am not clear.

Thank you!

You cannot currently copy data between Squarespace sites without third party tools or help from someone who has access to them.

An alternative way to build a new site is to use template preview mode on your existing site subscription, instead of starting a new trial. Install the new template and preview it. Everything will appear weird at first (no items on the nav etc) but don’t panic because you are the only one seeing this. Your website will still be running on the old template for the public to see.

During the preview, you can explore new layouts, colors and add new CSS.

Need to make a change to your live site? Cancel the template preview and you’ll see all the old settings again. When you want to work on the new version, just preview the template again and you’ll see all your work. It’s like having two sites in one. Just take care not to delete or move any content.

You'll find more information here: Switching templates.

thank you very much! I will try doing it like that. 
When I preview a new template, do I have to import my content again or does it automatically comes with the change of template?

The content remains, but it may be moved to 'UNLINKED' instead of appearing on the 'NAVIGATION'. Take care not to delete or edit content - it's the same content as the live site. The Squarespace guide explains which aspects you should change during preview, and which you should leave well alone.

Ah thank you I will check the links out.

Thank you for taking the time to answer!