Edit in JSFiddle

new Vue({
    el: "#app",
    data: {
        html: "<div>Hello World</div>",
    },
    computed: {
        output() {
            return this.html.replace(/[\u00A0-\u9999<>\&]/gim, (v) => '&#' + v.charCodeAt(0) + ';');
        }
    },
    methods: {},
    mounted() {}
})