react-cropper、react-easy-crop、react-image-crop はすべて React アプリケーションで画像をトリミング(クロップ)するための UI コンポーネントライブラリです。これらのライブラリは、ユーザーが画像をアップロードし、表示領域内で切り取り範囲を指定して最終的な画像を生成できるようにします。ただし、それぞれ異なるアプローチで実装されており、依存関係、API 設計、カスタマイズ性、出力処理の方法に明確な違いがあります。
画像のトリミング機能は、プロフィール写真の設定や商品画像の編集など、多くの Web アプリで必要になる機能です。React 向けにはいくつかのライブラリがありますが、それぞれ設計思想や用途が異なります。この記事では、react-cropper、react-easy-crop、react-image-crop の3つを、実際の開発者の視点から深く比較します。
react-cropper は、人気のある JavaScript ライブラリ Cropper.js の React ラッパーです。つまり、内部で DOM 操作を直接行う jQuery 風のライブラリを React で使うための橋渡し役です。そのため、React のライフサイクルとは少しズレた挙動を示すことがあります。
// react-cropper
import React, { useRef } from 'react';
import Cropper from 'react-cropper';
import 'cropperjs/dist/cropper.css';
function ImageCropper({ src }) {
const cropperRef = useRef(null);
const getCroppedDataUrl = () => {
const imageElement = cropperRef?.current;
const cropper = imageElement?.cropper;
return cropper.getCroppedCanvas().toDataURL();
};
return <Cropper src={src} ref={cropperRef} />;
}
react-easy-crop は、ゼロ依存で、純粋な React(hooks を活用)で書かれています。UI は CSS-in-JS で構築され、DOM 操作は一切行いません。ただし、画像の出力処理(canvas への描画)は含まれておらず、別途実装が必要です。
// react-easy-crop
import React, { useState } from 'react';
import Cropper from 'react-easy-crop';
function ImageCropper({ imageSrc }) {
const [crop, setCrop] = useState({ x: 0, y: 0 });
const [zoom, setZoom] = useState(1);
const onCropComplete = (croppedArea, croppedAreaPixels) => {
// croppedAreaPixels に { x, y, width, height } が入る
// 実際の画像生成は別途 canvas で行う必要がある
};
return (
<Cropper
image={imageSrc}
crop={crop}
zoom={zoom}
aspect={4 / 3}
onCropChange={setCrop}
onZoomChange={setZoom}
onCropComplete={onCropComplete}
/>
);
}
react-image-crop も軽量で、React 16.8+ の hooks に対応しています。独自の依存関係はなく、canvas 出力用のユーティリティ関数 getCroppedImg を同梱しています。
// react-image-crop
import React, { useState } from 'react';
import ReactCrop, { centerCrop, makeAspectCrop } from 'react-image-crop';
import 'react-image-crop/dist/ReactCrop.css';
function ImageCropper({ imgSrc }) {
const [crop, setCrop] = useState();
return (
<ReactCrop crop={crop} onChange={c => setCrop(c)}>
<img src={imgSrc} />
</ReactCrop>
);
}
これが最も重要な違いの一つです。
react-cropper: getCroppedCanvas() メソッドで直接 canvas を取得でき、そこから toDataURL() や toBlob() で画像を生成できます。出力処理は内蔵されています。
react-easy-crop: 出力処理は含まれていません。onCropComplete でピクセル単位の座標を受け取るだけです。実際に画像を切り抜くには、以下のような canvas 処理を自分で書く必要があります。
// react-easy-crop での画像出力例(公式ドキュメントより)
function createImage(url) {
return new Promise((resolve, reject) => {
const image = new Image();
image.addEventListener('load', () => resolve(image));
image.addEventListener('error', error => reject(error));
image.setAttribute('crossOrigin', 'anonymous');
image.src = url;
});
}
async function getCroppedImg(imageSrc, pixelCrop, rotation = 0) {
const image = await createImage(imageSrc);
const canvas = document.createElement('canvas');
const ctx = canvas.getContext('2d');
// ... canvas に描画して切り抜き処理 ...
return canvas.toDataURL('image/jpeg');
}
react-image-crop: getCroppedImg というユーティリティ関数が同梱されており、簡単に画像を生成できます。import { getCroppedImg } from 'react-image-crop';
const handleCropComplete = async (crop) => {
if (crop.width && crop.height) {
const croppedImg = await getCroppedImg(imgRef.current, crop);
// croppedImg は HTMLCanvasElement
}
};
react-cropper は最も高機能です。以下の操作が標準でサポートされています:
ただし、これらの機能を使うには Cropper.js 特有のオプション(例: viewMode, dragMode, rotatable)を理解する必要があります。
react-easy-crop は「切り取り枠の操作」に特化しています。ズーム、パン(移動)、アスペクト比固定は可能ですが、回転やフリップはサポートされていません。代わりに、UI の見た目(選択枠の色、ガイド線のスタイルなど)を細かくカスタマイズできます。
react-image-crop は基本的な切り取り機能(自由選択 or アスペクト比固定)のみを提供します。回転やフリップは非対応です。ただし、最小/最大サイズの制限や、初期切り取り位置の指定など、UX 向上のための細かい制御が可能です。
react-cropper は外部ライブラリに依存しているため、React の strict mode や concurrent features との互換性に注意が必要です。また、ref 経由でインスタンスメソッドを呼び出す必要があるため、テストがやや複雑になります。
react-easy-crop は props と callbacks だけで完結するため、ユニットテストが容易です。ただし、画像出力処理を自前で実装する手間があります。
react-image-crop はバランスが良く、すぐに動くサンプルが多く、学習コストが低いです。出力処理も同梱されているため、最小限のコードで機能を実現できます。
| 要件 | 推奨ライブラリ |
|---|---|
| 高度な編集機能(回転、フリップなど)が必要 | react-cropper |
| 軽量で、UI を細かくカスタマイズしたい | react-easy-crop |
| すぐに使えるシンプルなクロップ機能が欲しい | react-image-crop |
react-cropperreact-easy-cropreact-image-cropどのライブラリもメンテナンスされており、新規プロジェクトで安全に使用できます。あなたのプロジェクトの要件に最も合ったものを選んでください。
react-easy-crop は軽量で、モダンな React の書き方(hooks と関数型コンポーネント)を採用しています。主に「画像上に矩形の選択枠を表示し、その座標を取得する」ことに特化しており、実際に画像を canvas で加工する処理は含まれていません。そのため、出力処理を自分で実装する必要がありますが、その分柔軟性が高く、パフォーマンスも良好です。
react-image-crop はシンプルで直感的な API を持ち、canvas による画像の出力処理(getCroppedImg)を内蔵しています。依存関係が少なく、すぐに使えるクロップ機能を求めるプロジェクトに適しています。ただし、回転やフリップなどの高度な編集機能はサポートされておらず、カスタマイズ性はやや制限されます。
react-cropper は Cropper.js の React ラッパーであり、非常に豊富な機能(回転、拡大縮小、フリップ、ドラッグによる移動など)を提供します。既存の Cropper.js の API に慣れているチームや、高度な編集機能が必要なプロジェクトに向いています。ただし、Cropper.js に依存しているため、バンドルサイズが大きくなりやすく、純粋な React 的な設計とは言えません。
A React component to crop images/videos with easy interactions
Check out the examples:
If react-easy-crop doesn't cover your needs we recommend taking a look at Pintura
Pintura features cropping, rotating, flipping, filtering, annotating, and lots of additional functionality to cover all your image and video editing needs on both mobile and desktop devices.
yarn add react-easy-crop
or
npm install react-easy-crop --save
The Cropper is styled with
position: absoluteto take the full space of its parent. Thus, you need to wrap it with an element that usesposition: relativeor the Cropper will fill the whole page.
import { useState, useCallback } from 'react'
import Cropper from 'react-easy-crop'
const Demo = () => {
const [crop, setCrop] = useState({ x: 0, y: 0 })
const [zoom, setZoom] = useState(1)
const onCropComplete = (croppedArea, croppedAreaPixels) => {
console.log(croppedArea, croppedAreaPixels)
}
return (
<Cropper
image={yourImage}
crop={crop}
zoom={zoom}
aspect={4 / 3}
onCropChange={setCrop}
onCropComplete={onCropComplete}
onZoomChange={setZoom}
/>
)
}
This component requires some styles to be available in the document. By default, you don't need to do anything, the component will automatically inject the required styles in the document head. If you want to disable this behaviour and manually inject the CSS, you can set the disableAutomaticStylesInjection prop to true and use the file available in the package: react-easy-crop/react-easy-crop.css.
If you are using the Cropper inside a modal, you should ensure that there is no opening animation that is changing the modal dimensions (scaling effect). Fading or sliding animations are fine. See #428, #409, #267 or #400 for more details.
| Prop | Type | Required | Description |
|---|---|---|---|
image | string | The image to be cropped. image or video is required. | |
video | string or Array<{ src: string; type?: string }> | The video to be cropped. image or video is required. | |
crop | { x: number, y: number } | ✓ | Position of the media. { x: 0, y: 0 } will center the media under the cropper. |
zoom | number | Zoom of the media between minZoom and maxZoom. Defaults to 1. | |
rotation | number (in degrees) | Rotation of the media. Defaults to 0. | |
aspect | number | Aspect of the cropper. The value is the ratio between its width and its height. The default value is 4/3 | |
minZoom | number | Minimum zoom of the media. Defaults to 1. | |
maxZoom | number | Maximum zoom of the media. Defaults to 3. | |
zoomWithScroll | boolean | Enable zoom by scrolling. Defaults to true | |
cropShape | 'rect' | 'round' | Shape of the crop area. Defaults to 'rect'. | |
cropSize | { width: number, height: number } | Size of the crop area (in pixels). If you don't provide it, it will be computed automatically using the aspect prop and the media size. You should probably not use this option and should rely on aspect instead. See https://github.com/ValentinH/react-easy-crop/issues/186. | |
showGrid | boolean | Whether to show or not the grid (third-lines). Defaults to true. | |
roundCropAreaPixels | boolean | Whether to round the crop area dimensions to integer pixels. Defaults to false. | |
zoomSpeed | number | Multiplies the value by which the zoom changes. Defaults to 1. | |
objectFit demo | 'contain', 'cover', 'horizontal-cover' or 'vertical-cover' | Specifies how the image is shown in the cropper. contain: the image will be adjusted to be fully visible, horizontal-cover: the image will horizontally fill the cropper, vertical-cover: the image will vertically fill the cropper, cover: we automatically pick between horizontal-cover or vertical-cover to have a fully visible image inside the cropper area. Defaults to "contain". | |
onCropChange | crop => void | ✓ | Called every time the crop is changed. Use it to update your crop state. |
onZoomChange | zoom => void | Called every time the zoom is changed. Use it to update your zoom state. | |
onRotationChange | rotation => void | Called every time the rotation is changed (with mobile or multi-fingers gestures). Use it to update your rotation state. | |
onCropSizeChange | cropSize => void | Called when a change in either the cropSize width or the cropSize height occurs. | |
onCropComplete | Function | Called when the user stops moving the media or stops zooming. It will be passed the corresponding cropped area on the media in percentages and pixels (rounded to the nearest integer) | |
onCropAreaChange | Function | Very similar to onCropComplete but is triggered for every user interaction instead of waiting for the user to stop. | |
transform | string | CSS transform to apply to the image in the editor. Defaults to translate(${crop.x}px, ${crop.y}px) rotate(${rotation}deg) scale(${zoom}) with variables being pulled from props. | |
style | { containerStyle: object, mediaStyle: object, cropAreaStyle: object } | Custom styles to be used with the Cropper. Styles passed via the style prop are merged with the defaults. | |
classes | { containerClassName: string, mediaClassName: string, cropAreaClassName: string } | Custom class names to be used with the Cropper. Classes passed via the classes prop are merged with the defaults. If you have CSS specificity issues, you should probably use the disableAutomaticStylesInjection prop. | |
mediaProps | object | The properties you want to apply to the media tag ( | |
cropperProps | object | The properties you want to apply to the cropper. | |
restrictPosition | boolean | Whether the position of the media should be restricted to the boundaries of the cropper. Useful setting in case of zoom < 1 or if the cropper should preserve all media content while forcing a specific aspect ratio for media throughout the application. Example: https://codesandbox.io/s/1rmqky233q. | |
initialCroppedAreaPercentages | { width: number, height: number, x: number, y: number} | Use this to set the initial crop position/zoom of the cropper (for example, when editing a previously cropped media). The value should be the same as the croppedArea passed to onCropComplete. This is the preferred way of restoring the previously set crop because croppedAreaPixels is rounded, and when used for restoration, may result in a slight drifting crop/zoom | |
initialCroppedAreaPixels | { width: number, height: number, x: number, y: number} | Use this to set the initial crop position/zoom of the cropper (for example, when editing a previously cropped media). The value should be the same as the croppedAreaPixels passed to onCropComplete Example: https://codesandbox.io/s/pmj19vp2yx. | |
onInteractionStart | Function | Called every time a user starts a wheel, touch, mousedown or keydown (for arrow keys only) event. | |
onInteractionEnd | Function | Called every time a user ends a wheel, touch, mousedown or keydown (for arrow keys only) event. | |
onMediaLoaded | Function | Called when media gets loaded. Gets passed an mediaSize object like { width, height, naturalWidth, naturalHeight } | |
onTouchRequest | (e: React.TouchEvent<HTMLDivElement>) => boolean | Can be used to cancel a touch request by returning false. | |
onWheelRequest | (e: WheelEvent) => boolean | Can be used to cancel a zoom with wheel request by returning false. | |
disableAutomaticStylesInjection | boolean | Whether to auto inject styles using a style tag in the document head on component mount. When disabled you need to import the css file into your application manually (style file is available in react-easy-crop/react-easy-crop.css). Example with sass/scss @import "~react-easy-crop/react-easy-crop";. | |
setCropperRef | (ref: React.RefObject<HTMLDivElement>) => void | Called when the component mounts, if present. Used to set the value of the cropper ref object in the parent component. | |
setImageRef | (ref: React.RefObject<HTMLImageElement>) => void | Called when the component mounts, if present. Used to set the value of the image ref object in the parent component. | |
setVideoRef | (ref: React.RefObject<HTMLVideoElement>) => void | Called when the component mounts, if present. Used to set the value of the video ref object in the parent component. | |
setMediaSize | (size: MediaSize) => void | [Advanced Usage] Used to expose the mediaSize value for use with the getInitialCropFromCroppedAreaPixels and getInitialCropFromCroppedAreaPercentages functions. See this CodeSandbox instance for a simple example. | |
setCropSize | (size: Size) => void | [Advanced Usage] Used to expose the cropSize value for use with the getInitialCropFromCroppedAreaPixels and getInitialCropFromCroppedAreaPercentages functions. See this CodeSandbox instance for a simple example. | |
nonce | string | The nonce to add to the style tag when the styles are auto injected. | |
keyboardStep | number | number of pixels the crop area moves with each press of an arrow key when using keyboard navigation. Defaults to 1. |
This callback is the one you should use to save the cropped area of the media. It's passed 2 arguments:
croppedArea: coordinates and dimensions of the cropped area in percentage of the media dimensioncroppedAreaPixels: coordinates and dimensions of the cropped area in pixels.Both arguments have the following shape:
const area = {
x: number, // x/y are the coordinates of the top/left corner of the cropped area
y: number,
width: number, // width of the cropped area
height: number, // height of the cropped area
}
This is the exact same callback as onCropComplete, but is triggered for all user interactions.
It can be used if you are not performing any render action on it.
croppedArea: coordinates and dimensions of the cropped area in percentage of the media dimensioncroppedAreaPixels: coordinates and dimensions of the cropped area in pixels.Both arguments have the following shape:
const area = {
x: number, // x/y are the coordinates of the top/left corner of the cropped area
y: number,
width: number, // width of the cropped area
height: number, // height of the cropped area
}
Called when media gets successfully loaded. This is useful if you want to have a custom zoom/crop strategy based on media size.
Example:
const CONTAINER_HEIGHT = 300
const CroppedImage = ({ image }) => {
const [crop, onCropChange] = React.useState({ x: 0, y: 0 })
const [zoom, onZoomChange] = React.useState(1)
return (
<Cropper
image={image}
crop={crop}
zoom={zoom}
onCropChange={onCropChange}
onZoomChange={onZoomChange}
onMediaLoaded={(mediaSize) => {
// Adapt zoom based on media size to fit max height
onZoomChange(CONTAINER_HEIGHT / mediaSize.naturalHeight)
}}
/>
)
}
[Advanced Usage]
Used to calculate values for crop and zoom based on a desired croppedAreaPercentages
value. See this CodeSandbox instance for a simple example.
[Advanced Usage]
See getInitialCropFromCroppedAreaPercentages.
yarn
yarn start
Now, open http://localhost:3001/index.html and start hacking!
This project is maintained by Valentin Hervieu.
This project was originally part of @ricardo-ch organisation because I (Valentin) was working at Ricardo. After leaving this company, they gracefully accepted to transfer the project to me. ❤️
Thanks goes to these wonderful people (emoji key):
This project follows the all-contributors specification. Contributions of any kind welcome!