SOURCE

let vm = new Vue({
  el: '.app',
  data: {
    names: []
  }
})

<div class="app">
  <input type="checkbox" id="checkbox1" value="will" v-model="names" />
  <label for="checkbox1">will</label>
  <input type="checkbox" id="checkbox2" value="janet" v-model="names" />
  <label for="checkbox2">janet</label>
  <input type="checkbox" id="checkbox3" value="tom" v-model="names" />
  <label for="checkbox3">tom</label>
  <div>{{names | json}}</div>
</div>