Compare Images

Compare Two Images and See Exactly What Changed

Drop in an original and an edited version, and Compare Images marks every pixel that differs between them — an overlay you can tune with a difference threshold and recolor to whatever stands out against your image. A running percent-different readout tells you how much actually moved, and you can flip between Image A, Image B, the highlighted diff, and a drag-to-wipe swipe view.

It runs entirely in your browser on a native canvas — the two files never leave your device, there is no upload wait, and no account or watermark. Image B is automatically scaled to match A's dimensions so the two line up pixel for pixel, and the difference map exports as a clean PNG.

One honest note: this is a raster (pixel) comparison, not a semantic one. It sees how the images look, so re-saving a JPEG can introduce compression noise that reads as tiny differences — nudge the threshold up to ignore it. Comparing images with different aspect ratios stretches B to fit A, which is by design.

• Design QA: confirm a tweak only touched the button you meant to change and nothing else on the screen shifted.
• Before / after edits: see precisely which pixels a retouch, crop, or filter altered in a photo.
• Spot the difference: catch a swapped price, a moved logo, or an edited detail between two near-identical files.
• Screenshot regression: diff a UI screenshot from today against last week to find visual regressions in seconds.
• Print proofing: check that an exported artwork matches the approved version pixel for pixel before it goes to press.
• Compression checks: raise the threshold to judge how visible a compressor's or converter's changes really are.

Privacy: Compare Images runs entirely in your browser. Both images are decoded and compared locally on a canvas — nothing is uploaded, stored, or sent anywhere, so even confidential mockups and documents stay on your machine.