---
url: /docs/guide/usage/linter/rules/unicorn/prefer-global-this.md
---

### What it does

Enforces the use of [`globalThis`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/globalThis) instead of
environment‑specific global object aliases (`window`, `self`, or `global`).

Using the standard `globalThis` makes your code portable across browsers, Web Workers, Node.js,
and future JavaScript runtimes.

### Why is this bad?

**Portability** – `window` is only defined in browser main threads, `self` is used in Web Workers,
and `global` is Node‑specific. Choosing the wrong alias causes runtime crashes when the code is
executed outside of its original environment.

**Clarity** – `globalThis` clearly communicates that you are referring to the global object itself
rather than a particular platform.

### Examples

Examples of **incorrect** code for this rule:

```js
// Browser‑only
window.alert("Hi");

// Node‑only
if (typeof global.Buffer !== "undefined") {
}

// Web Worker‑only
self.postMessage("done");
```

Examples of **correct** code for this rule:

```js
globalThis.alert("Hi");

if (typeof globalThis.Buffer !== "undefined") {
}

globalThis.postMessage("done");
```

## How to use

## Version

This rule was added in v0.16.12.

## References