---
title: "no-buffer-constructor"
description: "Disallow the deprecated `Buffer()` constructor"
# Generated by src/codegen/lint-rule-docs.ts. Do not edit below this line.
plugin: "eslint"
aliases: ["eslint/no-buffer-constructor"]
kind: "problem"
category: null
default: "off"
fixable: "no"
typeAware: false
deprecated: true
---

`Buffer(value)` does different things depending on the type of `value`. A string is copied, and a number allocates that many bytes. If `value` comes from a request, a caller who sends a number where you expect a string gets to decide how much memory your server allocates.

Node.js has deprecated the constructor. `Buffer.from()`, `Buffer.alloc()` and `Buffer.allocUnsafe()` each do one thing, and `Buffer.from()` throws if it gets a number.

ESLint has deprecated this rule. Its replacement, `n/no-deprecated-api` from `eslint-plugin-n`, isn't built into `bun lint`.

## Examples

Reported:

{/* bad {"count": 2} */}
```js
const header = new Buffer(16);
const name = Buffer("Ada", "utf8");
```

Not reported:

{/* good */}
```js
const header = Buffer.alloc(16);
const name = Buffer.from("Ada", "utf8");
```