A side by side comparison helps when people are reviewing a retouch, a different crop or two product views. Keeping both whole images avoids hiding changes through an extra cover crop.
Image Comparison takes exactly two sources and fits them to one shared output height. A selected gap separates them on a solid background.
Ratios determine the widths
Two 400 by 300 images at a shared height of 600 each become 800 pixels wide. With a gap of 16, the combined canvas is 1616 by 600.
If the sources have different ratios, their widths differ. The tool preserves those ratios rather than forcing equal square panels.
A shared height can enlarge a smaller source. That helps align the display but does not create missing detail, so avoid judging sharpness as though both started at the same resolution.
Keep the comparison fair
Use versions representing the same intended view when you want to compare an edit. Different framing, lighting or scaling can explain a visible difference that has nothing to do with the processing step under review.
The tool does not calculate a pixel difference score, identify the better image or label one as an original automatically. Upload order controls left and right.
Transparent regions are composited onto the selected layout background. Choose a colour that makes relevant edges visible in both panels.
The combined canvas must remain within output limits. Reduce the shared height when two very wide sources make the result too large.
Download the composed image for discussion, while retaining the separate source files for closer inspection. A convenient comparison sheet is not a replacement for examining those originals at an appropriate scale.