●Change8

Migrating to Zod v4.3.4

Version v4.3.4 introduces 2 breaking changes. This guide details how to update your code.

Released: 12/31/2025

2
Breaking Changes
2
Migration Steps
4
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

ZodMiniTypelooseRecordfromJSONSchemapatternProperties

Breaking Changes

●Issue #1

Removed .refine() method from ZodMiniType, which may break custom validation logic relying on this method.

●Issue #2

Dropped ISO time support in fromJSONSchema conversion.

Migration Steps

  1. 1
    Replace usage of .refine() on ZodMiniType instances with alternative validation logic.
  2. 2
    Update JSON schema conversion logic if relying on ISO time formatting.

Release Summary

This release introduces patternProperties support for looseRecord and improves documentation, while removing the .refine() method from ZodMiniType and dropping ISO time in fromJSONSchema.

Need More Details?

View the full release notes and all changes for Zod v4.3.4.

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