Numarly

Crop Image

Drag to select a region and crop an image to it.

Click to select an image, or drag and drop it here

JPG, PNG, WebP, and other image formats

What is it?

This tool lets you drag a selection box directly on an image and crop it to exactly that area, entirely in your browser.

Formula Explanation

The image is displayed scaled down to fit the page, so your drag selection is tracked in on-screen pixels, then converted back to the image's original pixel dimensions using the display-to-original scale factor before cropping — so the downloaded file always uses the image's true resolution, not the shrunk preview size.

Example Calculation

On a 2000 × 1500 image shown at a 600px-wide preview (a 0.3× scale), a selection drawn 300 × 225 pixels on screen crops a 1000 × 750 pixel region from the original, full-resolution image.

How to Use

  1. Click the upload area or drag and drop an image onto it.
  2. Drag on the image preview to draw a selection box around the area to keep.
  3. Check the selection size shown below the preview.
  4. Click Crop & Download to save just that region.

Benefits

  • Crops visually by dragging directly on the image, no manual coordinate entry needed.
  • Processes everything locally in your browser — images are never uploaded anywhere.
  • Crops at the image's full original resolution, regardless of preview size.

Use Cases

  • Cutting an unwanted border or background out of a photo.
  • Isolating one subject from a group photo.
  • Trimming a screenshot down to just the relevant part.

What Your Result Means

The downloaded image contains only the pixels inside your selection, at the same resolution as that region in the original photo — nothing is scaled or resampled beyond the crop itself.

Tips

  • Drag slowly near the edges of the preview for finer control over the selection boundary.
  • Use Reset Selection to start over if your first drag wasn't quite right.
  • For a precise aspect ratio, watch the selection size readout while dragging.

Common Mistakes

  • Drawing a very small selection accidentally, which the tool ignores (drags under 5px are treated as a stray click).
  • Forgetting the crop uses the full-resolution image, so a small on-screen selection can still produce a large cropped image.
  • Selecting outside the visible image bounds — the selection is automatically clamped to the image edges.

FAQs

Are my images uploaded to a server?

No, all processing happens locally in your browser using the Canvas API — your images never leave your device.

Can I crop at an exact aspect ratio like 1:1 or 16:9?

Not with a locked ratio in this version — drag freely and use the live selection size readout to gauge the ratio as you go.

Can I adjust a selection after drawing it?

Not directly — draw a new selection to replace the previous one, or use Reset Selection to clear it and start over.

Does cropping reduce image quality?

No, the cropped region is copied at its original resolution with no recompression beyond the output format's own encoding.

Images are read and cropped locally in your browser and are never uploaded to a server.

Last updated: August 1, 2026