ImageToolKit

Compare Two Images Online — Side by Side Image Comparison [2026]

Upload two images → compare them side by side or with an interactive slider overlay. See dimension and file size differences at a glance. Free browser-based image comparison tool.

Image 1

Drop or click to browse

Image 2

Drop or click to browse

What is Compare Images?

Compare Images is a free online tool that lets you compare two images using side-by-side view or an interactive slider overlay. It displays file metadata (dimensions, file size, format) for both images so you can quickly spot differences. Ideal for comparing before/after edits, compression results, or different versions of the same image.

How to Use Compare Images

Upload two images by dragging them into the drop zones or clicking to browse. The tool displays both images side by side with their dimensions and file sizes. Switch to "Slider" mode to overlay the images with a draggable divider — drag left or right to reveal one image versus the other. This is perfect for comparing before/after edits, different compression levels, or format conversions.

How Compare Images Works

The tool loads both images using the FileReader API and displays them in the browser. In side-by-side mode, images are shown next to each other with metadata below. In slider mode, both images are overlaid and a draggable CSS divider controls a clip-path on the top image, revealing the bottom image as you drag. File metadata (dimensions, size, type) is extracted from the File object and Image element. All processing is client-side.

Common Use Cases

  • Compare before and after photo edits or retouching
  • Evaluate image compression quality at different settings
  • Compare different format conversions (PNG vs JPG vs WebP)
  • Spot differences between two versions of a design or graphic
  • Compare original vs resized images for quality assessment

Frequently Asked Questions

Do the two images need to be the same size?▼

No. The tool works with images of any size. In side-by-side mode, images are scaled to fit. In slider mode, both images are displayed at the same dimensions for accurate overlay comparison.

What comparison modes are available?▼

The tool offers two modes: Side-by-Side (images displayed next to each other) and Slider (images overlaid with a draggable divider to reveal one versus the other).

Can I compare images of different formats?▼

Yes. You can compare any combination of JPEG, PNG, WebP, GIF, or BMP images. This is useful for evaluating format conversion quality.

Does the tool detect pixel-level differences?▼

The tool provides visual comparison and metadata differences (size, dimensions). For pixel-level difference detection, a specialized diff tool would be needed.

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