Coerce

Zod · Reference cheat sheet

📋 Overview

z.coerce converts inputs before validation — useful for query strings, form fields, and env vars where everything arrives as strings.

🔧 Core concepts

💡 Examples

Query params:

const Query = z.object({
  page: z.coerce.number().int().min(1).default(1),
  q: z.string().optional(),
});
Query.parse({ page: "2", q: "zod" });

Env:

const Env = z.object({
  PORT: z.coerce.number().default(9000),
  DEBUG: z.coerce.boolean().default(false),
});

Dates:

z.coerce.date().parse("2026-07-11T00:00:00.000Z");

⚠️ Pitfalls

• z.coerce.boolean() treats any non-empty string as true — including "false". Prefer z.enum(['true','false']) + transform for forms.
• Coercion can hide bugs by accepting unexpected types.
• Prefer explicit transforms when conversion rules are domain-specific.

🔗 Related

• primitives.md
• transforms.md
• safeparse.md
• getting_started.md