Dart CI pub package


A Dart library providing the ability to load, save and manipulate images in a variety of different file formats.

The library is written entirely in Dart and has no reliance on dart:io, so it can be used for both server and web applications.

Performance Warning

Because this library is written entirely in Dart and is a not native executed library, its performance will not be as fast as a native library.

Supported Image Formats


  • PNG / Animated APNG
  • JPEG
  • Targa
  • GIF / Animated GIF
  • ICO
  • BMP

Read Only

  • WebP / Animated WebP
  • TIFF
  • Photoshop PSD
  • OpenEXR

Write Only

  • CUR




Format Decoding Functions


Load an image asynchronously and resize it as a thumbnail.

import 'dart:io';
import 'dart:isolate';
import 'package:image/image.dart';

class DecodeParam {
  final File file;
  final SendPort sendPort;
  DecodeParam(this.file, this.sendPort);

void decodeIsolate(DecodeParam param) {
  // Read an image from file (webp in this case).
  // decodeImage will identify the format of the image and use the appropriate
  // decoder.
  var image = decodeImage(param.file.readAsBytesSync())!;
  // Resize the image to a 120x? thumbnail (maintaining the aspect ratio).
  var thumbnail = copyResize(image, width: 120);

// Decode and process an image file in a separate thread (isolate) to avoid
// stalling the main UI thread.
void main() async {
  var receivePort = ReceivePort();

  await Isolate.spawn(
      decodeIsolate, DecodeParam(File('test.webp'), receivePort.sendPort));

  // Get the processed image from the isolate.
  var image = await receivePort.first as Image;

  await File('thumbnail.png').writeAsBytes(encodePng(image));


The image library aims to provide server-side programs the ability to load, manipulate, and save various image file formats.