Image Cropper

📘 How to Crop an Image Online

ToolZippy’s Image Cropper removes unwanted outer areas of an image and keeps only the rectangular region you select. Unlike resizing, cropping changes which part of the original image remains rather than simply changing its width and height.

✥ Visual Cropping and Exact Pixel Cropping

You can crop in two ways. For quick visual cropping, drag the selection rectangle over the part of the image you want to keep and resize it using the corner handles.

For precise work, use the X, Y, width and height fields. These values represent coordinates in the original image’s pixel dimensions, not just the smaller preview shown on the page.

X What Do X and Y Mean?

The image uses its top-left corner as the coordinate origin. An X value of 0 starts at the left edge, while a Y value of 0 starts at the top edge.

In this example, the crop begins 100 pixels from the left and 50 pixels from the top. It then keeps an area measuring 800 × 600 pixels.

▣ What Are Crop Width and Height?

Crop width determines how many horizontal pixels are retained, while crop height determines how many vertical pixels are retained.

The crop area must stay inside the original image. ToolZippy automatically constrains the values so the requested rectangle does not extend beyond the available image pixels.

↔ Cropping Is Different From Resizing

Cropping and resizing perform different jobs. Cropping removes areas around the edges and changes the visible composition. Resizing changes the dimensions of the complete image.

For example, cropping a 1920 × 1080 image to its central 1080 × 1080 area removes pixels from the left and right. Resizing the same image to 1080 × 1080 instead attempts to change the dimensions of the complete picture.

If you want to change dimensions without selecting a smaller region, use the Image Resizer.

▦ Aspect Ratio Presets

The preset buttons provide convenient starting crop shapes. A 1:1 crop creates a square selection, while 4:3, 3:2 and 16:9 create common rectangular proportions.

• 1:1 – square crop.
• 4:3 – traditional photo/display proportion.
• 3:2 – common photographic proportion.
• 16:9 – common widescreen proportion.
• Free Crop – no fixed aspect ratio is enforced.

The presets are starting selections rather than requirements for any particular website or social platform, whose recommended image sizes can change.

⌗ Original Pixels vs Preview Pixels

Large images are scaled down visually when necessary so they fit inside the browser page. That does not mean the original image is being reduced before cropping.

The editor converts the displayed crop rectangle back to the corresponding coordinates in the source image. The numeric fields therefore show source-image pixels.

PNG What Format Is the Cropped Image?

The cropped result is exported from the browser canvas as PNG. If the source contains transparency that the browser can decode, PNG can preserve transparent pixels in the selected region.

A PNG export can have a different file size from the original. If you need a smaller web file afterward, try the Image Compressor.

✓ Tips for Better Cropping

• Keep the important subject comfortably inside the crop boundary.
• Use an aspect-ratio preset when you need a particular shape.
• Use exact pixel fields when dimensions or coordinates matter.
• Avoid extremely small crops if you need a high-resolution final image.
• Keep the original image separately so you can make a different crop later.

🔒 Browser-Based Image Processing

The core cropping operation is designed to run in your browser. JavaScript reads the selected image, maps the crop coordinates to the source image and draws the selected rectangle to an HTML canvas.

Very large images can require more browser memory, especially on older phones or tablets. Image format support also depends on the browser’s ability to decode the selected file.

Continue editing with Image Resizer, Image Compressor, Image Brightness, Image Contrast or browse All Image Tools.