Image Comparison
Compare two images with a before-and-after slider, side by side, or a map that marks every difference. Free, on your device.
First image
Second image
Image Comparison shows two versions of a picture together so you can see what changed: drag a slider across them, view them side by side, or switch to a difference map that marks every changed pixel in bright pink. It also measures how much changed, the largest difference and the PSNR, a standard quality score. Use it to check an edit, compare two exports or compression settings, or spot what’s different between two screenshots.
How to use Image Comparison
- 1
Add both images
Drop or choose the first and the second image.
- 2
Choose a view
Slider, side by side, or the difference map.
- 3
Read the result
See how much changed and download the difference map.
What it does
- Three views
- A before-and-after slider, side by side, and a difference map.
- Measured
- Changed pixels, largest difference and PSNR.
- Adjustable
- Ignore tiny differences such as compression noise.
Questions
What does PSNR mean?
Peak signal-to-noise ratio: higher means more alike. Above about 40 dB differences are very hard to see; identical images have no PSNR.
Can I compare images of different sizes?
Yes. The second is scaled to the first’s size, which itself counts as a small difference.
Why are some pixels marked that look the same?
Lossy formats such as JPG change pixels slightly. Raise “Ignore differences up to” to hide those.
Is my picture uploaded?
No. It’s processed on your device and never leaves it.