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

> ajv@8.20.0 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

Another JSON Schema Validator

Last verified Sep 9, 2026 against ajv@8.20.0.

ajv ships CommonJS only. require("ajv") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "ajv" 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.

## What to do

1. require("ajv") 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 ajv from "ajv"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 8.20.0 (Apr 24, 2026)
- Module format: CommonJS
- Last CommonJS version: 8.20.0
- TypeScript types: bundled
- Node engines: not declared
- Weekly downloads: 332.4M
- License: MIT

## Runtime test results for ajv@8.20.0

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

| Runtime | require("ajv") | import "ajv" |
|---|---|---|
| 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 ajv

ES modules:

```js
import ajv from "ajv";
```

CommonJS:

```js
const ajv = require("ajv");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (315 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 6.9.1 – 8.20.0 | CommonJS | Feb 10, 2019 |

## Frequently asked

**Is ajv ESM-only?**

ajv@8.20.0 is a CommonJS package. ajv ships CommonJS only. require("ajv") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "ajv" 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 ajv with ES module syntax?**

Yes. import ajv from "ajv" 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 ajv work in Bun?**

Yes. import "ajv" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does ajv ship TypeScript types?**

Yes. ajv bundles its own type declarations; no @types package is needed.

## Links

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

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