---
title: Batch processing
description: Run several image operations in one native or WebAssembly call.
---

`batch()` records operations and executes them only when you request an image,
bytes, or a file. This avoids Dart-visible intermediate images.

## Encode a batch

```dart
final bytes = image
    .batch()
    .resize(800, 600)
    .grayscale()
    .encode(PixerJpegEncoder(quality: 85));
```

## Return an image

```dart
final result = image
    .batch()
    .crop(10, 10, 200, 200)
    .rotate90()
    .toImage();

try {
  print('${result.width}x${result.height}');
} finally {
  result.dispose();
}
```

## Save a batch

```dart
image.batch().resize(320, 240).saveToFile('thumbnail.png');
```

The original `Pixer` remains unchanged. Sequence-dependent validation, such as
crop bounds after a resize, is evaluated against the preceding operation's
output.

:::warning
`saveToFile` is unavailable in browser builds. Use `encode` and handle the
returned bytes instead.
:::