image-size

Fast, lightweight NodeJS package to get dimensions of any image file or buffer.

Key Features

• Zero dependencies
• Supports all major image formats
• Works with both files and buffers
• Minimal memory footprint - reads only image headers
• ESM and CommonJS support
• TypeScript types included

Supported formats

• BMP
• CUR
• DDS
• GIF
• HEIC (HEIF, AVCI, AVIF)
• ICNS
• ICO
• J2C
• JPEG-2000 (JP2)
• JPEG
• JPEG-XL
• KTX (1 and 2)
• PNG
• PNM (PAM, PBM, PFM, PGM, PPM)
• PSD
• SVG
• TGA
• TIFF
• WebP

Installation

npm install image-size
# or
yarn add image-size
# or
pnpm add image-size

Usage

Passing in a Buffer/Uint8Array

Best for streams, network requests, or when you already have the image data in memory.

import { imageSize } from 'image-size'
// or
const { imageSize } = require('image-size')

const dimensions = imageSize(buffer)
console.log(dimensions.width, dimensions.height)

Reading from a file

Best for local files. Returns a promise.

import { imageSizeFromFile } from 'image-size/fromFile'
// or
const { imageSizeFromFile } = require('image-size/fromFile')

const dimensions = await imageSizeFromFile('photos/image.jpg')
console.log(dimensions.width, dimensions.height)

Note: Reading from files has a default concurrency limit of 100 To change this limit, you can call the setConcurrency function like this:

import { setConcurrency } from 'image-size/fromFile'
// or
const { setConcurrency } = require('image-size/fromFile')
setConcurrency(123456)

Reading from a file Syncronously (not recommended) ⚠️

v1.x of this library had a sync API, that internally used sync file reads.

This isn’t recommended because this blocks the node.js main thread, which reduces the performance, and prevents this library from being used concurrently.

However if you still need to use this package syncronously, you can read the file syncronously into a buffer, and then pass the buffer to this library.

import { readFileSync } from 'node:fs'
import { imageSize } from 'image-size'

const buffer = readFileSync('photos/image.jpg')
const dimensions = imageSize(buffer)
console.log(dimensions.width, dimensions.height)

3. Command Line

Useful for quick checks.

npx image-size image1.jpg image2.png

Multi-size

If the target file/buffer is an HEIF, an ICO, or a CUR file, the width and height will be the ones of the largest image in the set.

An additional images array is available and returns the dimensions of all the available images

import { imageSizeFromFile } from 'image-size/fromFile'
// or
const { imageSizeFromFile } = require('image-size/fromFile')

const { images } = await imageSizeFromFile('images/multi-size.ico')
for (const dimensions of images) {
  console.log(dimensions.width, dimensions.height)
}

Using a URL

import url from 'node:url'
import http from 'node:http'
import { imageSize } from 'image-size'

const imgUrl = 'http://my-amazing-website.com/image.jpeg'
const options = url.parse(imgUrl)

http.get(options, function (response) {
  const chunks = []
  response
    .on('data', function (chunk) {
      chunks.push(chunk)
    })
    .on('end', function () {
      const buffer = Buffer.concat(chunks)
      console.log(imageSize(buffer))
    })
})

Disabling certain image types

import { disableTypes } from 'image-size'
// or
const { disableTypes } = require('image-size')

disableTypes(['tiff', 'ico'])

JPEG image orientation

If the orientation is present in the JPEG EXIF metadata, it will be returned by the function. The orientation value is a number between 1 and 8 representing a type of orientation.

import { imageSizeFromFile } from 'image-size/fromFile'
// or
const { imageSizeFromFile } = require('image-size/fromFile')

const { width, height, orientation } = await imageSizeFromFile('images/photo.jpeg')
console.log(width, height, orientation)

Limitations

1. Partial File Reading

   • Only reads image headers, not full files
   • Some corrupted images might still report dimensions

2. SVG Limitations

   • Only supports pixel dimensions and viewBox
   • Percentage values not supported

3. File Access

   • Reading from files has a default concurrency limit of 100
   • Can be adjusted using setConcurrency()

4. Buffer Requirements

   • Some formats (like TIFF) require the full header in buffer
   • Streaming partial buffers may not work for all formats

License

MIT

Credits

not a direct port, but an attempt to have something like dabble’s imagesize as a node module.

Contributors