Whether you're reviewing design revisions, checking print proofs, or verifying that a website update looks correct, comparing two images by eye is slow and unreliable. You'll miss subtle colour changes, shifted elements, and small text edits.
ChangeChecks automates this with pixel-level image comparison — upload two images and see exactly what changed.
How it works
The tool analyses both images pixel by pixel using the Canvas API in your browser. It identifies every area that differs between the two versions and calculates the overall similarity percentage.
Four ways to view differences
Slider mode lets you drag a vertical divider across the image, revealing the original on one side and the edited version on the other. This is the fastest way to spot changes in context.
Fade mode crossfades between both images using an opacity slider. Subtle changes — colour shifts, minor repositioning — become visible as flickering when you move the slider.
Side by side shows both images at the same scale for direct comparison. Changed regions are highlighted with tinted overlays.
Difference mode shows only the pixels that changed, with everything else greyed out. This is the most precise view — it reveals changes that are invisible to the naked eye.
What the summary tells you
The summary bar shows the percentage of pixels that changed, the image dimensions, and the overall similarity score. A context line describes where the changes are concentrated (e.g. "top-right area" or "bottom section").
Below the main comparison, a breakdown shows how many regions were added, removed, or modified, with visual bars showing the proportion.
Best for
Designers comparing mockup revisions. QA teams verifying website or app changes between deployments. Print production teams checking proofs against approved artwork. Marketing teams reviewing ad creative revisions.