How to add password matching validation in vuetify?

You can define custom rules:

computed: {    passwordConfirmationRule() {      return () => (this.password === this.rePassword) || 'Password must match'    }}

and use it

 <v-flex xs12 sm6>    <v-text-field                  v-model="rePassword"      :append-icon="show1 ? 'visibility' : 'visibility_off'"      :rules="[rules.required, rules.min, passwordConfirmationRule]"      :type="show1 ? 'text' : 'password'"      name="input-10-1"      label="Re-enter Password"      hint="At least 8 characters"      counter      @click:append="show1 = !show1"    />  </v-flex>

very easiest way isusing v-model (password and confirm_password), no need to use computation

Rule

:rules="[v => !!v || 'field is required']"

Or

:rules="[(password!="") || 'field is required']"

in password

<v-text-field label="Password*" v-model="password" type="password" required   :rules="[v => !!v || 'field is required']"></v-text-field>                

confirm password fieldRule

 :rules="[(password === confirm_password) || 'Password must match']"

code:

 <v-text-field label="Confirm Password*" v-model="confirm_password" type="password"  required   :rules="[(password === confirm_password) || 'Password must match']"></v-text-field>                    

VeeValidate is great for form validation but in my opinion is overkill for resolving this question when it can be achieved in Vuetify alone.

Following on from @ittus answer, you need to remove the arrow function in passwordConfirmationRule to access this:

      return this.password === this.rePassword || "Password must match";

See this codesandbox working example (also now using Vuetify 2.x)