Snap Crop

A React image cropping component with both Crop Mode and Fill Mode.

✨ Features

• 🖼️ Crop Mode: Crop images by adjusting the crop frame with zoom and pan
• ⭕ Circular Crop: Support for circular cropping masks
• 📐 Fill Mode: Position images within a fixed frame with customizable fill color
• 📝 Aspect Ratios: Support for 16:9, 9:16, 1:1, 4:3, 3:4
• 💾 Export: Export to JPEG, PNG, or WebP with quality control
• 📱 Responsive: Works on desktop and mobile
• ⚡ Controlled & Uncontrolled: Supports both controlled and uncontrolled usage patterns
• 🔧 Flexible API: Pass through all react-easy-crop props for full customization

📦 Installation

npm install snap-crop

yarn add snap-crop

pnpm add snap-crop

Peer Dependencies

This package requires the following peer dependencies:

npm install react react-dom react-easy-crop

Styling Dependency

This package uses TailwindCSS for styling. Make sure your project has TailwindCSS configured. If you haven't set up TailwindCSS yet:

npm install tailwindcss @tailwindcss/vite

Then configure TailwindCSS in your project according to the official documentation.

🚀 Quick Start

import { useRef } from "react";
import { SnapCrop, SnapCropRef } from "snap-crop";

function App() {
  const snapCropRef = useRef<SnapCropRef>(null);

  const handleExport = async () => {
    await snapCropRef.current?.export({
      format: "jpeg",
      quality: 0.9,
      filename: "cropped-image.jpg",
    });
  };

  return (
    <div style={{ width: "100%", height: "500px" }}>
      <SnapCrop
        ref={snapCropRef}
        image="/path/to/image.jpg"
        aspect="16:9"
        mode="crop"
        fillColor="#FFFFFF"
      />
      <button onClick={handleExport}>Export</button>
    </div>
  );
}

📖 Usage Examples

Basic Crop Mode

import { SnapCrop, SnapCropRef } from "snap-crop";

function CropExample() {
  const ref = useRef<SnapCropRef>(null);

  return (
    <div style={{ width: "600px", height: "400px" }}>
      <SnapCrop
        ref={ref}
        image="/photo.jpg"
        aspect="16:9"
        mode="crop"
        showGrid={true}
      />
    </div>
  );
}

Circular Crop

function CircularCropExample() {
  const ref = useRef<SnapCropRef>(null);

  return (
    <div style={{ width: "400px", height: "400px" }}>
      <SnapCrop
        ref={ref}
        image="/avatar.jpg"
        aspect="1:1"
        mode="crop"
        cropShape="round"
        showGrid={false}
      />
    </div>
  );
}

Fill Mode with Custom Color

function FillExample() {
  const ref = useRef<SnapCropRef>(null);

  return (
    <div style={{ width: "600px", height: "400px" }}>
      <SnapCrop
        ref={ref}
        image="/photo.jpg"
        aspect="9:16"
        mode="fill"
        fillColor="#000000"
      />
    </div>
  );
}

Controlled Zoom & Position

You can control the zoom level and crop position externally:

function ControlledExample() {
  const ref = useRef<SnapCropRef>(null);
  const [zoom, setZoom] = useState(1);
  const [crop, setCrop] = useState({ x: 0, y: 0 });

  return (
    <div>
      <input
        type="range"
        min={1}
        max={3}
        step={0.1}
        value={zoom}
        onChange={(e) => setZoom(Number(e.target.value))}
      />
      <span>{zoom.toFixed(1)}x</span>

      <div style={{ width: "600px", height: "400px" }}>
        <SnapCrop
          ref={ref}
          image="/photo.jpg"
          aspect="16:9"
          mode="crop"
          zoom={zoom}
          onZoomChange={setZoom}
          crop={crop}
          onCropPositionChange={setCrop}
        />
      </div>
    </div>
  );
}

Export as Blob

Use getBlob() to get the image as a Blob for uploading:

const handleUpload = async () => {
  const blob = await snapCropRef.current?.getBlob({
    format: "png",
    quality: 1,
  });

  if (blob) {
    const formData = new FormData();
    formData.append("file", blob, "image.png");
    await fetch("/api/upload", { method: "POST", body: formData });
  }
};

📋 API Reference

SnapCrop Props

Crop Mode Control Props

Cropper Props (passed through from react-easy-crop)

SnapCrop Ref Methods

Access these methods via useRef:

const snapCropRef = useRef<SnapCropRef>(null);

export(options?)

Export the current crop/fill result as a downloaded file.

await snapCropRef.current?.export({
  format: "jpeg", // 'jpeg' | 'png' | 'webp'
  quality: 0.9, // 0-1 (for jpeg and webp only)
  filename: "image.jpg",
});

getBlob(options?)

Get the current crop/fill result as a Blob.

const blob = await snapCropRef.current?.getBlob({
  format: "png",
  quality: 1,
});

reset()

Reset crop/fill to default position and zoom.

snapCropRef.current?.reset();

🎨 Styling

This component uses TailwindCSS for styling. Ensure TailwindCSS is configured in your project.

The component uses the following CSS class names that you can target for customization:

Custom Styling Example

You can use the className prop to add additional Tailwind classes:

<SnapCrop
  className="rounded-lg overflow-hidden shadow-lg"
  // ... other props
/>

Or target the class names in your custom CSS:

.snap-crop {
  border-radius: 8px;
  overflow: hidden;
}

.fill-mode .fill-frame {
  border-radius: 4px;
}

📤 Exported Utilities

The package also exports utility functions:

import {
  // Image processing
  getCroppedImg,
  getFilledImg,
  downloadBlob,
  createImage,
  getExtension,

  // File validation
  validateImageFile,
  fileToDataUrl,
  getImageDimensions,

  // Constants
  ASPECT_RATIOS,
  DEFAULT_SIZES,
  PRESET_COLORS,
  MIN_IMAGE_SIZE,
  MAX_IMAGE_SIZE,
  MAX_FILE_SIZE,
} from "snap-crop";

🛠️ Development

# Install dependencies
npm install

# Start dev server
npm run dev

# Build library
npm run build:lib

# Type check
npm run typecheck

# Lint
npm run lint

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the project
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

📄 License

MIT © Lupeiwen0