Image Compare

Upload two images, compare them pixel by pixel, and get a difference ratio plus a red-highlighted difference map — a quick way to pinpoint exactly what changed.

Image A

Drop an image or click to upload

Image B

Drop an image or click to upload

What Is Image Comparison?

The Image Compare tool analyzes two images pixel by pixel, computes an overall difference ratio, and highlights differing regions in red while dimming the identical parts.

It's commonly used to verify whether an image was modified, check design-versus-implementation gaps, and compare screenshots of different versions.

How to Compare Two Images

Three steps to compare two images:

  • Upload image A and image B in the two areas above (PNG, JPG, WEBP, or BMP supported).
  • Click Compare to get the difference ratio and difference map.
  • To keep the result, click Download Diff to save the comparison output.

Tips

  • Using same-size images of the same content gives the clearest comparison.
  • A lower difference ratio means the two images are closer to identical.
  • To quickly check whether two images show the same content, run the Image Perceptual Hash tool first.

Frequently Asked Questions

How is the difference ratio calculated?+
The second image is resized to match the first, then the two are compared pixel by pixel. Pixels whose color difference exceeds a threshold are counted as different, and their share of the total is the difference ratio.
What does red mean in the difference map?+
Red highlights mark the areas where the two images differ. Everything else is dimmed so you can spot every difference at a glance.
Can I compare images of different sizes?+
Yes. The tool automatically resizes the second image to match the first before comparing pixel by pixel.
Is my image uploaded anywhere?+
No. All comparison happens locally in your browser — your images never leave your device.

Related Tools

Duplicate Image FinderImage Perceptual HashImage Histogram

Image Compare — free online image compare, compare images, image difference, diff image, spot the difference, image comparison. No signup required. Works in your browser.