Get site template by Powershell
With these few lines you can find out, what site template is used by which site collection
$webapp = Get-SPWebApplication -identity https://webapplicationUrl
$webtem = Get-spwebtemplate
#Get all site collections with publishing site template
$webapp.Sites | Where-Object {(Get-SPWeb $_.URL).WebTemplate -match "CMSPUBLISHING"}
#or
foreach ($site in $webapp.Sites)
{
$spweb = get-spweb $site.URL
write-host “Site URL: ” $site.URL
write-host “Web Template: ” $spweb.WebTemplate
write-host “WebTemplateID: ” $spweb.WebTemplateID
write-host “————————————-”
}