# Is @stencil/core ESM-only? Can you require() it?

> @stencil/core@4.44.2 ships CommonJS and ESM builds. Dual package — require() works on every Node.js version we test; import works too.

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Last verified Sep 9, 2026 against @stencil/core@4.44.2.

@stencil/core publishes both a CommonJS entry and a native ESM entry (ESM added in 4.19.0). require("@stencil/core") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=16.0.0. import "@stencil/core" works alongside it.

## What to do

1. Nothing to change. require("@stencil/core") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=16.0.0. import * as core from "@stencil/core" works alongside it; use named imports for what the ESM entry exports.
2. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 4.44.2 (Aug 26, 2026)
- Module format: Dual (CommonJS + ESM)
- Last CommonJS version: 4.44.2
- Native ESM since: 4.19.0
- TypeScript types: bundled
- Node engines: >=16.0.0
- Weekly downloads: 1.2M
- License: MIT

## Runtime test results for @stencil/core@4.44.2

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

| Runtime | require("@stencil/core") | import "@stencil/core" |
|---|---|---|
| Node.js 18 | works | fails (SyntaxError) |
| 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 @stencil/core

ES modules:

```js
import * as core from "@stencil/core";
```

Namespace import shown because the ESM entry may have no default export; use named imports for what it exports.

CommonJS:

```js
const core = require("@stencil/core");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (385 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 4.22.1 – 4.44.2 | Dual (CommonJS + ESM) | Oct 9, 2024 |

## Frequently asked

**Is @stencil/core ESM-only?**

@stencil/core@4.44.2 ships CommonJS and ESM builds. @stencil/core publishes both a CommonJS entry and a native ESM entry (ESM added in 4.19.0). require("@stencil/core") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=16.0.0. import "@stencil/core" works alongside it.

**Can I require @stencil/core?**

Yes. @stencil/core ships a CommonJS entry alongside the native ESM entry. require("@stencil/core") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=16.0.0.

**Does @stencil/core work in Bun?**

Yes. import "@stencil/core" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does @stencil/core ship TypeScript types?**

Yes. @stencil/core bundles its own type declarations; no @types package is needed.

## Links

- [@stencil/core on npm](https://www.npmjs.com/package/@stencil/core)
- [Source repository](https://github.com/stenciljs/core)
- [HTML version](https://canirequire.com/package/@stencil/core/)
- [JSON version](https://canirequire.com/package/@stencil/core.json)

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