### Setup Zod repository for local benchmarks

Source: https://zod.dev/v4?id=an-extensible-foundation-zodv4core

Commands to clone the Zod repository, switch to the v4 branch, and install dependencies for benchmarking.

```bash
$ git clone git@github.com:colinhacks/zod.git
$ cd zod
$ git switch v4
$ pnpm install
```

--------------------------------

### Zod Mini Bundle Size Example

Source: https://zod.dev/v4?id=65x-faster-object-parsing

Minimal example demonstrating Zod Mini's tree-shakable API, resulting in 1.88kb gzipped bundle (85% reduction vs Zod 3).

```typescript
import * as z from "zod/mini";
 
const schema = z.boolean();
schema.parse(false);
```

--------------------------------

### Set Up Zod 4 Benchmarks Repository

Source: https://zod.dev/v4?id=65x-faster-object-parsing

Clone the Zod repository, switch to the v4 branch, and install dependencies to run performance benchmarks locally.

```bash
$ git clone git@github.com:colinhacks/zod.git
$ cd zod
$ git switch v4
$ pnpm install
```

--------------------------------

### Setup and Run Zod 4 Benchmarks

Source: https://zod.dev/v4?id=custom-email-regex

Commands to clone the Zod repository, switch to the v4 branch, and execute specific benchmarks.

```bash
$ git clone git@github.com:colinhacks/zod.git
$ cd zod
$ git switch v4
$ pnpm install
```

```bash
$ pnpm bench <name>
```

--------------------------------

### Zod Mini Bundle Size Example

Source: https://zod.dev/v4?id=an-extensible-foundation-zodv4core

Demonstrates the significant bundle size reduction when using Zod Mini. This example produces a 1.88kb gzipped bundle, an 85% reduction compared to Zod 3.

```typescript
import * as z from "zod/mini";
 
const schema = z.boolean();
schema.parse(false);
```

--------------------------------

### Install Zod 4

Source: https://zod.dev/v4/changelog?id=deprecates-message-parameter

Install the stable Zod 4 version using npm.

```bash
npm install zod@^4.0.0
```

--------------------------------

### Clone and set up Zod repository for benchmarks

Source: https://zod.dev/v4

Commands to clone the Zod repository, switch to the v4 branch, and install dependencies using pnpm, preparing for benchmark execution.

```bash
$ git clone git@github.com:colinhacks/zod.git
$ cd zod
$ git switch v4
$ pnpm install
```

--------------------------------

### Basic Zod Mini Schema Usage

Source: https://zod.dev/v4

A simple example demonstrating schema definition and parsing using Zod Mini, highlighting its smaller bundle size.

```typescript
import * as z from "zod/mini";
 
const schema = z.boolean();
schema.parse(false);
```

--------------------------------

### Example of Pretty-Printed Zod Error Output

Source: https://zod.dev/v4?id=benchmarks

Illustrates the multi-line string output generated by `z.prettifyError()` for the example `ZodError` provided.

```text
✖ Unrecognized key: "extraField"
✖ Invalid input: expected string, received number
  → at username
✖ Invalid input: expected number, received string
  → at favoriteNumbers[1]
```

--------------------------------

### Zod v4 `tsc` Instantiation Reduction Example

Source: https://zod.dev/v4?id=65x-faster-object-parsing

This example demonstrates a simple Zod schema definition using `z.object` and `extend`, which shows significant `tsc` instantiation reduction in Zod v4 compared to v3.

```typescript
import * as z from "zod";
 
export const A = z.object({
  a: z.string(),
  b: z.string(),
  c: z.string(),
  d: z.string(),
  e: z.string()
});
 
export const B = A.extend({
  f: z.string(),
  g: z.string(),
  h: z.string()
});
```

--------------------------------

### Equivalent .meta() for .describe()

Source: https://zod.dev/v4?id=stringbool

Shows how to achieve the same result as `.describe()` using the preferred `.meta()` method for adding a description.

```typescript
z.string().meta({ description: "An email address" });
```

--------------------------------

### Example of Pretty-Printed ZodError Output

Source: https://zod.dev/v4

Shows the multi-line string output generated by z.prettifyError for a ZodError instance, providing a user-friendly format.

```text
✖ Unrecognized key: "extraField"
✖ Invalid input: expected string, received number
  → at username
✖ Invalid input: expected number, received string
  → at favoriteNumbers[1]
```

--------------------------------

### Describe Schema with .describe() Method

Source: https://zod.dev/v4?id=an-extensible-foundation-zodv4core

Use `.describe()` for backward compatibility with Zod 3, though `.meta()` is preferred. Both methods add metadata to the global registry.

```typescript
z.string().describe("An email address");
 
// equivalent to
z.string().meta({ description: "An email address" });
```

--------------------------------

### Migrate from .describe() to .meta()

Source: https://zod.dev/v4?id=100x-reduction-in-tsc-instantiations

`.describe()` remains available for Zod 3 compatibility but `.meta()` is the preferred approach for adding descriptions and other metadata.

```typescript
z.string().describe("An email address");
 
// equivalent to
z.string().meta({ description: "An email address" });
```

--------------------------------

### Create ZodError for Pretty Printing

Source: https://zod.dev/v4?id=65x-faster-object-parsing

Provides an example of manually constructing a `ZodError` instance containing multiple validation issues, suitable for processing by `z.prettifyError`.

```typescript
const myError = new z.ZodError([
  {
    code: 'unrecognized_keys',
    keys: [ 'extraField' ],
    path: [],
    message: 'Unrecognized key: "extraField"'
  },
  {
    expected: 'string',
    code: 'invalid_type',
    path: [ 'username' ],
    message: 'Invalid input: expected string, received number'
  },
  {
    origin: 'number',
    code: 'too_small',
    minimum: 0,
    inclusive: true,
    path: [ 'favoriteNumbers', 1 ],
    message: 'Too small: expected number to be >=0'
  }
]);
 
z.prettifyError(myError);
```

--------------------------------

### Add and Retrieve Schemas from Registry

Source: https://zod.dev/v4?id=2x-reduction-in-core-bundle-size

Use myRegistry.add() to associate a schema with metadata, and myRegistry.get() to retrieve it. Alternatively, use the .register() method on the schema itself.

```javascript
const emailSchema = z.string().email();
 
myRegistry.add(emailSchema, { title: "Email address", description: "..." });
myRegistry.get(emailSchema);
// => { title: "Email address", ... }
```

```javascript
emailSchema.register(myRegistry, { title: "Email address", description: "..." })
// => returns emailSchema
```

--------------------------------

### Equivalent `.meta()` for `.describe()`

Source: https://zod.dev/v4

Shows the `.meta()` equivalent for setting a schema description, which is the preferred approach in Zod 4.

```typescript
z.string().meta({ description: "An email address" });
```