Just include this code to your css file
[v-cloak] { display:none; }
https://vuejs.org/api/built-in-directives.html#v-cloak
Usage example:
<div class="xpto" v-cloak>
Hello
</div>
This directive will remain on the element until the associated Vue
instance finishes compilation. Combined with CSS rules such as
[v-cloak] { display: none }, this directive can be used to hide
un-compiled mustache bindings until the Vue instance is ready.