Finding SiteTemplate type in SharePoint 2010 & 2013

Many a times, we may not have access to the SharePoint environment. But we may want to know the SharePoint Site Template type without logging into the Servers and without using Site Settings/Administration.

Here are the steps:

1) View the Page source(In IE, Right Click on the page and click View Source. In Chrome, Click Ctrl + I).
Search for the Keyword g_wsaSiteTemplateId

If you see something like var g_wsaSiteTemplateId = 'STS#0';, then the site was created using Team Site. You can map the value of g_wsaSiteTemplateId  to a specific Site Template.
For example 'STS#0' is the code for Team Site

2) If you want to know all templates open PowerShell and run 

Get-SPWebTemplate | format-table -auto | Out-File -FilePath  "C:\temp\Output.txt" 

You will get a list of all templates

If you don't have a local SharePoint environment, you can find them from Bernd Kemmler's Blog

3) Some of the most commonly used  are

• STS#0        Team Site
• STS#1        Blank Site
• WIKI#0      Wiki Site
• BLOG#0     Blog Site
• CMSPUBLISHING#0  Publishing Site               
• BLANKINTERNET#0  Publishing Site                                                     

Thats it.

Good Luck.