Well, that's a strange question. I guess you are talking about compiling string templates.
It seems obvious that you can't pre-compile your template without any dedicated build tool.
You have at least two solutions to use Vue without build engine, but none of them includes pre-compiling of string templates:
Use the full build of Vue (with compiler included), which can compile your string templates on the fly during execution. It's actually very lightweight and (almost) unnoticeable performance-wise for small to medium app. If you don't want to use any commonJS module and only use it in script tag, you can use the UMD build. It is availible there: https://unpkg.com/vue
You can use render functions directly instead of templates, so you don't need to compile anything. See: https://v2.vuejs.org/v2/guide/render-function.html