Screenshot Comparison
Compare two local screenshots pixel by pixel with threshold and heatmap. See the diff share and download the diff image.
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The result will appear here …
Compare screenshots: pixel diff with threshold
Load two local screenshots, for example before and after a design change or two states of a page. The comparison shows both images side by side and computes the differences pixel by pixel. A threshold controls from which deviation a pixel counts as different, so mild compression artifacts do not distort every value.
The result states the share of differing pixels in percent and shows a heatmap where changed areas light up. Download the heatmap as PNG and attach it to a ticket or a piece of feedback. Both images must have identical dimensions, if they differ the tool tells you. Everything runs locally in the browser.
Frequently asked questions
Why do my screenshots differ in size?
Different zoom levels, device pixel ratios or cropped edges change the dimensions. The comparison needs exactly equal sizes because it matches pixel against pixel. Scale the images to the same format first.
What does the threshold do?
It sets how far two pixels must differ in color to count as a change. A high value ignores JPEG noise and antialiasing, a low one finds subtle shifts too. Try 2 to 5 percent as a starting point.
What is the screenshot comparison good for day to day?
Classically design QA: did the CSS update really move the button? Also for regression checks on landing pages or comparing two language versions of the same layout.