Zod Friendly Forms

Transform Zod validation errors into user-friendly form error messages.

The Problem

Zod gives you great validation, but its error messages aren’t ready for end users:

// Zod's raw error output
{
  "email": [
    {
      "code": "invalid_string",
      "message": "Invalid email",
      "path": ["email"]
    }
  ]
}

The Solution

Get clean, user-ready error messages that you can display directly in your forms:

import { parseForm } from "@jmondi/zod-friendly-forms";

const { errors } = parseForm({ schema, data });

// Clean, user-friendly output
{
  "email": "Invalid email"
}

Quick Start

import { z } from "zod";
import { parseForm } from "@jmondi/zod-friendly-forms";

const schema = z.object({
  email: z.string().email(),
  password: z.string().min(8)
});

const formData = {
  email: "invalid-email",
  password: "123"
};

const { errors, validData } = parseForm({ schema, data: formData });

if (errors) {
  console.log(errors);
  // {
  //   email: "Invalid email",
  //   password: "String must contain at least 8 character(s)"
  // }
} else {
  console.log(validData); // Fully typed and validated data
}

Features

• ✅ User-friendly error messages - Ready to display to end users
• ✅ Type-safe validation - Fully typed validated data
• ✅ Framework agnostic - Works with React, Vue, Svelte, vanilla JS
• ✅ FormData support - Handles web forms, URLSearchParams, and plain objects
• ✅ Nested object errors - Flattened dot-notation keys (e.g., user.email)
• ✅ Server & client - Use anywhere JavaScript runs

Version Compatibility

• zod-friendly-forms v4.0+: Supports Zod v4.x
• zod-friendly-forms v2.0: Use this version for Zod v3.x compatibility

Installation

npm/pnpm

pnpm add zod
pnpm dlx jsr add @jmondi/zod-friendly-forms

Deno

deno add @jmondi/zod-friendly-forms

Usage

Basic Usage

import { z } from "zod";
import { parseForm } from "@jmondi/zod-friendly-forms";

const schema = z.object({
  email: z.string().email(),
});

const { errors, validData } = parseForm({ 
  schema, 
  data: { email: "bob@example.com" } 
});

if (!errors) {
  // validData is fully typed as { email: string }
  console.log(validData.email); // TypeScript knows this is a string
}

With FormData

Works seamlessly with HTML forms:

const formData = new FormData();
formData.append("email", "invalid-email");

const { errors } = parseForm({ schema, data: formData });
// { email: "Invalid email" }

Nested Objects

Handles complex nested validation with flattened error keys:

const schema = z.object({
  user: z.object({
    email: z.string().email(),
    profile: z.object({
      name: z.string().min(2)
    })
  })
});

const { errors } = parseForm({ 
  schema, 
  data: { 
    user: { 
      email: "invalid", 
      profile: { name: "x" } 
    } 
  } 
});

console.log(errors);
// {
//   "user.email": "Invalid email",
//   "user.profile.name": "String must contain at least 2 character(s)"
// }

Options

const { errors, validData } = parseForm(
  { schema, data },
  { stripEmptyStrings: true } // Convert empty strings to undefined
);

Framework Examples

React

import { useState } from "react";
import { z } from "zod";
import { parseForm } from "@jmondi/zod-friendly-forms";

const LoginSchema = z.object({
  email: z.string().email(),
  password: z.string().min(8),
});

export function LoginForm() {
  const [formData, setFormData] = useState({ email: "", password: "" });
  const [errors, setErrors] = useState({});

  const handleSubmit = async (e) => {
    e.preventDefault();
    const { errors, validData } = parseForm({ 
      schema: LoginSchema, 
      data: formData 
    });
    
    if (errors) {
      setErrors(errors);
    } else {
      // Handle successful login with validData
      await login(validData);
    }
  };

  return (
    <form onSubmit={handleSubmit}>
      <input 
        type="email" 
        value={formData.email}
        onChange={(e) => setFormData({...formData, email: e.target.value})}
      />
      {errors.email && <span className="error">{errors.email}</span>}
      
      <input 
        type="password" 
        value={formData.password}
        onChange={(e) => setFormData({...formData, password: e.target.value})}
      />
      {errors.password && <span className="error">{errors.password}</span>}
      
      <button type="submit">Login</button>
    </form>
  );
}

Svelte

<script lang="ts">
  import { z } from "zod";
  import { parseForm } from "@jmondi/zod-friendly-forms";

  const schema = z.object({
    email: z.string().email(),
    password: z.string().min(8),
  });

  let formData = { email: "", password: "" };
  let errors = {};

  async function handleSubmit() {
    const result = parseForm({ schema, data: formData });
    if (result.errors) {
      errors = result.errors;
    } else {
      await login(result.validData);
    }
  }
</script>

<form on:submit|preventDefault={handleSubmit}>
  <input bind:value={formData.email} type="email" />
  {#if errors.email}<span class="error">{errors.email}</span>{/if}
  
  <input bind:value={formData.password} type="password" />
  {#if errors.password}<span class="error">{errors.password}</span>{/if}
  
  <button type="submit">Login</button>
</form>

Vue

<template>
  <form @submit.prevent="handleSubmit">
    <input v-model="formData.email" type="email" />
    <span v-if="errors.email" class="error">{{ errors.email }}</span>
    
    <input v-model="formData.password" type="password" />
    <span v-if="errors.password" class="error">{{ errors.password }}</span>
    
    <button type="submit">Login</button>
  </form>
</template>

<script>
import { z } from 'zod';
import { parseForm } from '@jmondi/zod-friendly-forms';

const schema = z.object({
  email: z.string().email(),
  password: z.string().min(8),
});

export default {
  data() {
    return {
      formData: { email: "", password: "" },
      errors: {}
    };
  },
  methods: {
    async handleSubmit() {
      const { errors, validData } = parseForm({ 
        schema, 
        data: this.formData 
      });
      
      if (errors) {
        this.errors = errors;
      } else {
        await this.login(validData);
      }
    }
  }
};
</script>

API Reference

parseForm(params, options?)

Parameters:

• params.schema - Zod schema for validation
• params.data - Form data (object, FormData, or URLSearchParams)
• options.stripEmptyStrings - Convert empty strings to undefined (optional)

Returns:

• Success: { validData: T, errors: undefined }
• Failure: { errors: Record<string, string>, validData: undefined }

License

MIT