Handling Zod Errors

Purpose

Comprehensive guide to error handling in Zod v4, covering the unified error API, custom error messages, error formatting, and integration with UI frameworks.

Unified Error API

Overview

Zod v4 unified all error customization under a single error parameter, replacing multiple deprecated parameters.

v3 (deprecated):

z.string({ message: "Required" });
z.string({ invalid_type_error: "Must be string" });
z.string({ required_error: "Field required" });
z.object({}, { errorMap: customMap });