Star import vs named imports

[shivan-eyespace]

Hi all,

I am not sure if this has been asked before but is there any difference between:

import * as z from "zod"

as opposed to

import { z, ZodError } from "zod"

EDIT: This would be for using zod v4

[dosubot[bot]]

Hi @shivan-eyespace! I'm Dosu and I’m helping the zod team.

There is a practical difference between star imports (import * as z from "zod") and named imports (import { z, ZodError } from "zod") when using Zod. Star imports are generally recommended because they work better with tree-shaking in most bundlers (like Webpack, esbuild, and Next.js), resulting in smaller bundle sizes. Named imports can lead to bundlers including the entire Zod object, making tree-shaking less effective and potentially increasing your bundle size see discussion.

Some bundlers—especially Next.js with Turbopack—can also throw runtime errors (such as ReferenceError: Cannot access 'ZodEnum' before initialization) when using named imports, due to module initialization order issues. Star imports avoid these errors by ensuring the whole module is loaded before use see issue.

The Zod documentation and maintainers consistently use and recommend star imports for best compatibility and performance docs. If minimizing bundle size is critical, you might also want to look into zod/mini, which is designed for maximum tree-shakability.

If this answers your question, feel free to close the issue!

To reply, just mention @dosu.

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