Joi vs Zod for validation in Node.js APIs

[TahaAyati-DevLab]

I'm currently using Joi for request validation in a Node.js/Express API, and I'm considering learning Zod as well.

For a backend project that is mainly written in JavaScript, what are the practical differences between Joi and Zod?

I'm particularly interested in:

• Error handling
• Custom validation
• Nested object validation
• Schema reuse
• Performance
• TypeScript support

For someone building Node.js APIs without heavily relying on TypeScript, are there any significant advantages to choosing Zod over Joi?

[charles-benedito]

honest take for plain js: the main zod win is z.infer giving u types, and without typescript thats gone. error handling, custom rules and nesting are close to joi, .safeParse() vs .validate(), .refine() vs any.custom(), .extend() vs .keys()

zod is smaller and faster (2kb core, zod 4 got quick) and newer libs speak it natively, but if joi already works id propably not rewrite anything. hope that helps