Vue 3 Form Patterns

v-model is the foundation. Add vee-validate when validation grows beyond simple HTML5 attributes.

Detection

Marker (in deps)	Library
vee-validate (+ @vee-validate/zod or @vee-validate/yup)	vee-validate (recommended)
@vueuse/core	VueUse helpers (lighter alternative)
(none)	Native v-model + HTML5 validation
zod / yup / valibot	Pair with vee-validate via resolver

Native v-model (sufficient for simple forms)

<script setup lang="ts">
import { ref } from 'vue';

const email = ref('');
const password = ref('');
const remember = ref(false);

function onSubmit() {
  // ...
}
</script>

<template>
  <form @submit.prevent="onSubmit">
    <input v-model="email" type="email" required placeholder="Email" />
    <input v-model="password" type="password" required minlength="8" placeholder="Password" />
    <label>
      <input v-model="remember" type="checkbox" /> Remember me
    </label>
    <button>Log in</button>
  </form>
</template>

Built-in HTML5 validation (required, type="email", pattern, minlength, maxlength) is free. Use it for forms ≤3 fields with simple rules.

v-model modifiers

<input v-model.lazy="text" />          <!-- updates on change, not input -->
<input v-model.number="age" />          <!-- coerces to number -->
<input v-model.trim="username" />       <!-- trims whitespace -->

v-model on custom components

In Vue 3.4+, use defineModel:

<!-- CustomInput.vue -->
<script setup lang="ts">
const value = defineModel<string>();
const error = defineModel<string | null>('error', { default: null });
</script>

<template>
  <div>
    <input v-model="value" />
    <p v-if="error" class="error">{{ error }}</p>
  </div>
</template>

<!-- Parent -->
<CustomInput v-model="form.email" v-model:error="emailError" />

For Vue 3.0–3.3, use manual props + emits:

<script setup lang="ts">
const props = defineProps<{ modelValue: string }>();
const emit = defineEmits<{ 'update:modelValue': [value: string] }>();

function onInput(e: Event) {
  emit('update:modelValue', (e.target as HTMLInputElement).value);
}
</script>

<template>
  <input :value="props.modelValue" @input="onInput" />
</template>

vee-validate (recommended for non-trivial forms)

pnpm add vee-validate @vee-validate/zod zod

Basic form

<script setup lang="ts">
import { useForm } from 'vee-validate';
import { toTypedSchema } from '@vee-validate/zod';
import { z } from 'zod';

const schema = toTypedSchema(z.object({
  email: z.string().email('Invalid email'),
  password: z.string().min(8, 'At least 8 characters'),
  remember: z.boolean().default(false),
}));

const { defineField, handleSubmit, errors, isSubmitting } = useForm({
  validationSchema: schema,
  initialValues: { email: '', password: '', remember: false },
});

const [email, emailAttrs] = defineField('email');
const [password, passwordAttrs] = defineField('password');
const [remember, rememberAttrs] = defineField('remember');

const onSubmit = handleSubmit(async (values) => {
  await login(values);
});
</script>

<template>
  <form @submit="onSubmit">
    <label>
      Email
      <input v-model="email" v-bind="emailAttrs" type="email" />
      <p v-if="errors.email" role="alert">{{ errors.email }}</p>
    </label>

    <label>
      Password
      <input v-model="password" v-bind="passwordAttrs" type="password" />
      <p v-if="errors.password" role="alert">{{ errors.password }}</p>
    </label>

    <label>
      <input v-model="remember" v-bind="rememberAttrs" type="checkbox" />
      Remember me
    </label>

    <button :disabled="isSubmitting">
      {{ isSubmitting ? 'Logging in...' : 'Log in' }}
    </button>
  </form>
</template>

Field components alternative

<script setup lang="ts">
import { Field, ErrorMessage, useForm } from 'vee-validate';
import { toTypedSchema } from '@vee-validate/zod';
import { z } from 'zod';

useForm({
  validationSchema: toTypedSchema(z.object({
    email: z.string().email(),
    password: z.string().min(8),
  })),
});
</script>

<template>
  <form>
    <Field name="email" type="email" />
    <ErrorMessage name="email" as="p" role="alert" />

    <Field name="password" type="password" />
    <ErrorMessage name="password" />
  </form>
</template>

<Field> and <ErrorMessage> are convenient but less flexible. Pick one approach per project.

Field arrays

<script setup lang="ts">
import { useForm, useFieldArray } from 'vee-validate';

const { handleSubmit } = useForm({
  initialValues: { contacts: [{ email: '' }] },
});
const { fields, push, remove } = useFieldArray<{ email: string }>('contacts');
</script>

<template>
  <form @submit="handleSubmit(onSubmit)">
    <div v-for="(field, index) in fields" :key="field.key">
      <Field :name="`contacts[${index}].email`" type="email" />
      <ErrorMessage :name="`contacts[${index}].email`" />
      <button type="button" @click="remove(index)">Remove</button>
    </div>
    <button type="button" @click="push({ email: '' })">Add</button>
    <button type="submit">Save</button>
  </form>
</template>

field.key is a stable key from vee-validate — DON'T use index.

Async validation

const schema = z.object({
  username: z.string().min(3).refine(
    async (u) => {
      const res = await fetch(`/api/users/check?u=${u}`);
      return (await res.json()).available;
    },
    'Username taken'
  ),
});

const { defineField } = useForm({
  validationSchema: toTypedSchema(schema),
  validateOnInput: false,
  validateOnBlur: true,                    // validate on blur — appropriate for expensive checks
});

Server error handling

const { handleSubmit, setErrors, setFieldError } = useForm({...});

const onSubmit = handleSubmit(async (values) => {
  try {
    await createUser(values);
  } catch (err) {
    if (err instanceof FetchError && err.status === 409) {
      setFieldError('email', 'Email already in use');
    } else {
      setErrors({ form: 'Something went wrong' });
    }
  }
});

Multi-step forms

<script setup lang="ts">
import { useForm } from 'vee-validate';
import { ref } from 'vue';

const step = ref(0);
const { defineField, validate, values, handleSubmit } = useForm({
  validationSchema: schema,
  initialValues: { step1: {}, step2: {} },
});

async function next() {
  const result = await validate();        // validates whole form
  if (result.valid) step.value++;
  // OR validate just current step's fields:
  // const r = await validate({ mode: 'silent' });
  // if (r.valid) step.value++;
}

const onSubmit = handleSubmit((vals) => save(vals));
</script>

<template>
  <form @submit="onSubmit">
    <Step1 v-if="step === 0" />
    <Step2 v-if="step === 1" />
    <button v-if="step < lastStep" type="button" @click="next">Next</button>
    <button v-else type="submit">Submit</button>
  </form>
</template>

VueUse useForm (lighter alternative)

@vueuse/core doesn't have a direct useForm equivalent. For simple forms, native v-model + manual validation is enough. For complex forms, use vee-validate.

VueUse useful form-related composables:

• useDebouncedRef — debounce input value.
• useStorage — persist form state to localStorage (NEVER for sensitive data).
• onClickOutside — close dropdowns / pickers.
• useFocus — focus management for accessibility.

Integration with TanStack Query / Pinia

<script setup lang="ts">
import { useForm } from 'vee-validate';
import { toTypedSchema } from '@vee-validate/zod';
import { z } from 'zod';
import { useCreateUser } from '@/composables/useUsers';
import { useRouter } from 'vue-router';

const router = useRouter();
const { mutate: createUser, isPending } = useCreateUser();

const schema = toTypedSchema(z.object({
  email: z.string().email(),
  name: z.string().min(1),
}));

const { handleSubmit, setFieldError, defineField } = useForm({ validationSchema: schema });
const [email, emailAttrs] = defineField('email');
const [name, nameAttrs] = defineField('name');

const onSubmit = handleSubmit(async (values) => {
  createUser(values, {
    onSuccess: () => router.push('/users'),
    onError: (err) => {
      if (err.status === 409) setFieldError('email', 'Email already in use');
    },
  });
});
</script>

Accessibility checklist

• Every input has a <label> (visible or via aria-label).
• aria-invalid on inputs with errors.
• role="alert" on error messages (or aria-live="polite").
• Focus moves to first error on submit failure.
• Submit button shows loading state.

Anti-patterns

• ❌ Mutating props directly to update form values (use defineModel or emit).
• ❌ Skipping client-side validation thinking server suffices — UX suffers.
• ❌ Skipping server-side validation thinking client suffices — security suffers.
• ❌ Validating on every keystroke for expensive checks (DB lookup) — debounce or validateOnBlur.
• ❌ Forgetting to disable submit button while submitting — leads to double-submits.
• ❌ Persisting form state to localStorage when it contains PII — privacy concern.
• ❌ Resetting form to empty after server error — user re-types from scratch.
• ❌ Both vee-validate and formkit in same project without clear boundary.