Is it possible to create duplicate SharePoint site ( like save as option) ?

This method is totally a legacy solution and should not be relied upon and it now fails when you try and save the site template file in any case with an error message:

Unable to convert the HeaderColorIndexInLightMode XML attribute for the WebTemplate XML element for feature {eb336846-9820-4ec8-a767-3b7bb5bb778e} to a positive integer value.

The proposed new approach is to use Site Designs https://learn.microsoft.com/en-us/sharepoint/dev/declarative-customization/get-started-create-site-design but that is not the same as it amounts to running a series of post provisioning scripts that add lists and libraries etc. but this has its limitations (no content for example)

The ability to save a site as a proper and complete template was a staple of on-prem SharePoint for decades and Microsoft would do well to bring this capability back in a way that properly support SPO and modern sites. My bet is that they won't though - too much effort.

Msft has hidden the save template option for some unknown reason but because they never do a "real" update like most competent companies, you can still access it by appending /_layouts/savetmpl.aspx to your site's url. There are some other roadblocks created by Msft when it comes to creating a site from a template, but post back if you need help with that.

Keep in mind too, if you get an access denied error when you try to save, you'll need to enable custom scripting by running this in powershell:

Connect-SPOService -Url https://xxx-admin.sharepoint.com

Set-SPOSite -Identity https://xxx.sharepoint.com/sites/xxx -DenyAddAndCustomizePages 0

Requires the Sharepoint management shell on local machine.

I am trying to do this as well. Why are the simplest things so difficult to do with Microsoft?

I saved a site as a template. It saved successfully. However when I go to "Create a new site" I don't have the option to locate the template and use it for the new site. When I look under the tab that says "Organization" it says I don't have any templates listed there. Also when I follow these instructions below the types of site to create I don't have an "Other options" listed there.

See screen shots. However if I go to some place called solutions, I see my template there as a .wsp file but no way to apply it as a new site.

Microsoft is maddening sometimes.

I cannot follow the steps in Tina's reply because I'm using macOS.

It's also impossible to use SPOServices on Azure Cloud Shell.

These features should not be hidden behind flags, special command line arguments, or code. This feature should be exposed in the UI.

Fix it.

I have the same problem. Launched the site for department a year ago and I remember working on 2 clones before launching the best one. There was an option to duplicate.

I spend a good 3 to 4 hours just looking for where is that duplicate option and can't find it.

Your way is not helpful in my case. I followed the steps but there is no option to save site as template :(