Check a design against its implementation, compare two screenshots for visual regressions, or find what changed between two photos. Diffspot decodes both images in your browser and computes a perceptual pixel difference that ignores anti-aliasing noise, then lets you inspect it five ways with synchronized zoom.
How to compare two images
- Drop the original image on the left: PNG, JPEG, WebP, GIF, AVIF, BMP or SVG. You can paste a screenshot too.
- Drop the changed image on the right.
- Pick a view Side by side, Slider, Fade, Flicker or Difference (keys 1–5).
- Zoom in on details with ⌘/Ctrl + scroll; both images move together.
Why Diffspot
- Five ways to lookSide by side, a swipe slider, an opacity fade, a flicker toggle and a highlighted difference map.
- Anti-aliasing awarePixels that differ only by edge smoothing are recognized and not counted as changes.
- Exact numbersSee the share of changed pixels, the changed area, and size differences.
- Download the diffSave the difference map as a PNG.
- Never uploadedImages are decoded and compared locally.
- Free, no accountEvery feature is free with no sign-up and no size paywall. Ads pay for the site, and they run in an isolated frame that can't read the page.
Frequently asked questions
Can I compare images of different sizes?
Yes. They're aligned at the top-left corner and the size difference is reported.
How is the difference computed?
Each pixel pair is compared using a perceptual color distance (YIQ). Pixels above the sensitivity threshold count as changed unless they're identified as anti-aliasing.
Is it safe to paste confidential text or files?
Yes. Diffspot computes every comparison on your device: the page loads the engine once, then your text and files stay in the browser tab. There is no upload and no server-side storage, and ads are shown in a separate sandboxed frame that cannot read the page. How Diffspot works explains the details, and you can confirm it in your browser's network panel.
Is Diffspot free?
Yes. All features are free, with no account, no trial and no limit on the number of comparisons. The site is supported by ads, which never see what you compare.