Zod 4 – The Next Evolution in TypeScript Validation

Zod 4 is now stable, bringing significant performance improvements, reduced bundle size, and long-requested features to TypeScript schema validation.

1️⃣ Why Zod 4?

✅ 14x Faster String Parsing – Optimized validation speeds up processing.

✅ 7x Faster Array Parsing – Improves efficiency for large datasets.

✅ 6.5x Faster Object Parsing – Reduces overhead in complex schemas.

✅ 100x Reduction in TypeScript Instantiations – Enhances compiler performance.

✅ 2x Smaller Core Bundle – Minimizes package size for better tree-shaking.

2️⃣ Key Features & Enhancements

✅ Zod Mini – A lightweight, tree-shakable variant for strict bundle size constraints.

✅ Metadata & Registries – Attach structured metadata to schemas for better documentation.

✅ JSON Schema Conversion – First-party support for generating JSON Schema from Zod schemas.

✅ Recursive Objects – Native support for defining recursive types without workarounds.

✅ File Schema Validation – Built-in support for validating File instances.

✅ Internationalization – New locales API for translating error messages.

✅ Error Pretty-Printing – Improved formatting for debugging validation errors.

✅ Top-Level String Formats – More concise and tree-shakable validation methods.

✅ Template Literal Types – Enables validation of TypeScript template literals.

✅ Number Formats – Supports fixed-width integer and float types.

✅ Stringbool Parsing – Converts common string representations ("true", "false") into booleans.

✅ Discriminated Union Upgrades – Supports unions and pipes for more flexible validation.

3️⃣ Migration & Versioning

✅ Zod 4 is initially published alongside Zod 3 as part of zod@3.25.

✅ To upgrade:

npm upgrade zod@^3.25.0

import { z } from "zod/v4";

✅ Future Release: Zod 4 will eventually be published as zod@4.0.0 with full ecosystem support.

Final Thoughts

Zod 4 fixes long-standing limitations, making TypeScript validation faster, more efficient, and more scalable. Whether you're working on backend APIs, frontend validation, or complex data structures, Zod 4 provides unmatched flexibility and performance.