Zod is a TypeScript-first schema library that lets developers define data structures once and automatically generates both runtime validators and static TypeScript types. Its chainable API provides safe parsing, async validation, and transformations, ensuring incoming JSON or API payloads match the expected types without extra boilerplate.
Funding
Funding not disclosed
Founders
Product
Problem
JavaScript and TypeScript projects often lack reliable runtime validation of external data, leading to type mismatches, uncaught errors, and fragile codebases. Developers must manually write repetitive checks or rely on loosely typed APIs, which increases bug risk and maintenance overhead.
Solution
Zod provides a TypeScript-first schema library that generates runtime validators and compile-time type inference from a single source of truth. By defining schemas in code, developers obtain automatic type checking during development and robust validation of incoming data at runtime. The library integrates seamlessly with existing TypeScript projects, offering a concise, chainable API that eliminates boilerplate validation logic. Zod’s inference engine extracts static TypeScript types from schemas, ensuring consistency between validation and type definitions without extra code generation steps.
Target Audience
Primary users are TypeScript developers building web, server, or full‑stack applications who need reliable data validation and type safety, including teams adopting API‑driven architectures or working with external JSON payloads.
Features
- Declarative schema definitions with a fluent, chainable API for objects, arrays, enums, unions, and custom refinements
- Automatic TypeScript type inference from schemas, keeping runtime validation and static types in sync
- Safe parsing methods (`parse`, `safeParse`) that return detailed error objects for precise debugging
- Support for async validation, transformations, and default values to handle complex data pipelines
- Zero‑dependency, tree‑shakable package optimized for both Node.js and browser environments
- Compatibility with popular frameworks and libraries (e.g., Express, React, Next.js) via simple middleware adapters