The default PHP version on Templ.io today is PHP 7.3.
We also provide support for PHP 7.0, PHP 7.1 as well as 7.2 for all all our customers upon request
Our recommendation is to always run the most modern stable version of PHP that your application supports. It is almost always faster, more secure and better maintained. It will also give your application the longest possible potential life, as opposed to choosing tech that is soon to be discontinued.
We recommend all new WordPress sites to run at least PHP 7.2 for maximum performance, stability and longevity.
All our web servers can support different PHP versions for different websites, meaning that if you have two websites running on the same sever, one of them can run PHP 7.2 while the other runs PHP 7.0 for example.
To change PHP version for your Templ.io hosted website, simply contact our support and we will help you perform the change.