Image Comparison (Before / After)
Compare two images with a before/after slider or highlight the pixels that differ.
See the difference between two images
Use Image Comparison to see how much a photo changed after editing or compression, the differences between two design versions, or what changed between old and new screenshots of a web page.
Two view modes
- Before/after slider: overlays the images and lets you drag between them
- Difference view: marks changed pixels in red and reports the percentage of the image that changed
Use cases
Ideal for judging compression quality, presenting retouching before/after, catching visual regressions in UI tests and finding differences between two similar photos. Both images are processed in your browser.
How to use Image Comparison (Before / After)
- Upload the first (before) image.
- Upload the second (after) image.
- Choose the slider or difference view.
- Inspect the differences and the changed-pixel percentage.
Why use this tool?
Spot even the smallest change between two images in seconds without uploading your files.
FAQ
Do the images need to be the same size?
No. The second image is scaled to the size of the first so they can be compared pixel by pixel.
What does the difference percentage mean?
It's the share of pixels whose colour differs by more than a threshold, relative to the total pixel count.
Does JPG compression show up as differences?
Yes, compression creates small colour shifts that can appear as scattered dots in the difference view.
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