---
url: /docs/replacements/gzip-size.md
description: >-
  Native Node.js alternatives to the gzip-size for calculating gzipped size of a
  string or buffer
---

# Replacements for `gzip-size`

## `gzipSync` (native, since Node.js 9.4.0)

To calculate the gzipped size of a string or an `ArrayBuffer`, you can use [gzipSync](https://nodejs.org/api/zlib.html#zlibgzipsync) which exist inside the `zlib` module:

### Synchronous

```ts
import { gzipSizeSync } from 'gzip-size' // [!code --]
import { gzipSync } from 'node:zlib' // [!code ++]

const text = 'Lorem ipsum dolor sil amet'

console.log(gzipSizeSync(text)) // [!code --]
console.log(gzipSync(text).length) // [!code ++]
```

### Asynchronous

```ts
import { gzipSize } from 'gzip-size' // [!code --]
import { gzipSync } from 'node:zlib' // [!code ++]
import { promisify } from 'node:util' // [!code ++]

const gzipAsync = promisify(gzip) // [!code ++]

const text = 'Lorem ipsum dolor sil amet'

console.log(await gzipSize(text)) // [!code --]
console.log((await gzipAsync(text)).length) // [!code ++]
```

### Calculating from a file

```ts
import { gzipSizeFromFileSync } from 'gzip-size' // [!code --]
import { gzipSync } from 'node:zlib' // [!code ++]
import { readFileSync } from 'node:fs' // [!code ++]

const path = '/path/to/file'

console.log(gzipSizeFromFileSync(path)) // [!code --]
console.log(gzipSync(readFileSync(path)).length) // [!code ++]
```