# Is async-validator ESM-only? Can you require() it?

> async-validator@4.2.5 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

validate form asynchronous

Last verified Sep 9, 2026 against async-validator@4.2.5.

async-validator ships CommonJS only. require("async-validator") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "async-validator" also works because Node.js and Bun can import CommonJS from ES modules, but only the default export is guaranteed; named imports depend on Node's static analysis of the module.

It also declares a "module" field, so bundlers such as webpack, Vite and esbuild pick up an ESM build for tree-shaking.

## What to do

1. require("async-validator") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun.
2. From ES modules use the default import: import asyncValidator from "async-validator"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 4.2.5 (Jun 17, 2022)
- Module format: CommonJS
- Last CommonJS version: 4.2.5
- TypeScript types: bundled
- Node engines: not declared
- Weekly downloads: 1.6M
- License: MIT

## Runtime test results for async-validator@4.2.5

Installed and executed on Sep 9, 2026 with require("async-validator") from a CommonJS file and import "async-validator" from an ES module.

| Runtime | require("async-validator") | import "async-validator" |
|---|---|---|
| Node.js 18 | works | works |
| Node.js 20 | works | works |
| Node.js 22 | works | works |
| Node.js 24 | works | works |
| Node.js 26 | works | works |
| Bun 1.4.0 | works | works |

## How to import async-validator

ES modules:

```js
import asyncValidator from "async-validator";
```

CommonJS:

```js
const asyncValidator = require("async-validator");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (86 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 1.6.1 – 4.2.5 | CommonJS | Mar 30, 2016 |

## Frequently asked

**Is async-validator ESM-only?**

async-validator@4.2.5 is a CommonJS package. async-validator ships CommonJS only. require("async-validator") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "async-validator" also works because Node.js and Bun can import CommonJS from ES modules, but only the default export is guaranteed; named imports depend on Node's static analysis of the module.

**Can I import async-validator with ES module syntax?**

Yes. import asyncValidator from "async-validator" works in Node.js and Bun because they support importing CommonJS modules. Named imports work only when Node.js can statically detect the exports.

**Does async-validator work in Bun?**

Yes. import "async-validator" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does async-validator ship TypeScript types?**

Yes. async-validator bundles its own type declarations; no @types package is needed.

## Links

- [async-validator on npm](https://www.npmjs.com/package/async-validator)
- [Source repository](https://github.com/yiminghe/async-validator)
- [HTML version](https://canirequire.com/package/async-validator/)
- [JSON version](https://canirequire.com/package/async-validator.json)

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