How to Compare Two Versions of an Image Side by Side
Eyeballing two similar photos in separate browser tabs and flicking between them is a surprisingly unreliable way to catch differences — your eyes adjust between glances and small changes slip right past. A proper side-by-side or slider comparison removes that problem entirely by putting both images in the same frame at the same time.
Steps
- Open the Image Compare Tool.
- Upload the two images you want to compare — an original and an edited version, two compression settings of the same photo, a before-and-after.
- Drag the slider (or use whichever comparison view the tool offers) to sweep across the frame and spot exactly where the two diverge.
Where this is genuinely useful
Checking how much detail a compression setting actually costs you before committing to it is the most common use here — run the same photo through the Image Compressor at two different quality levels, then compare both against the original at 100% zoom rather than trusting a thumbnail preview, since compression artifacts are exactly the kind of thing that hides at small size and shows up the moment you look closely.