Introducing the Visual Website Diff Tool — Compare Any Two Pages Side-by-Side
Spot Visual Differences Instantly
We just shipped a free visual website diff tool — enter two URLs and see them side by side, with a pixel-level difference map and an interactive slider overlay. No signup, no API key, no account.
It's built on top of SnapShot API, our screenshot-as-a-service that gives you instant API keys via curl.
Three Ways to Compare
The tool offers three comparison modes:
Side by Side
Both pages rendered at full width with their dimensions displayed. Useful for a quick visual scan.
Interactive Slider
A before/after slider overlay. Drag left and right to reveal one page underneath the other. This is the most natural way to spot layout shifts, missing elements, or content changes.
Pixel Difference Map
An automated diff that highlights every changed pixel in magenta. Screens that are identical will show no magenta at all — a powerful check for CI/CD visual regression testing.
The tool also computes a difference percentage and total changed pixel count.
Use It in CI/CD
The curl command at the bottom of the page shows the programmatic equivalent:
curl -o staging.png "https://snapshot-api-production-1374.up.railway.app/screenshot?url=https://staging.example.com&key=YOUR_KEY" curl -o prod.png "https://snapshot-api-production-1374.up.railway.app/screenshot?url=https://prod.example.com&key=YOUR_KEY" compare staging.png prod.png diff.png
Drop this into your GitHub Actions or CI pipeline and reject deploys that exceed a pixel-diff threshold.
Built with SnapShot API
Each comparison fetches two screenshots via the SnapShot API playground endpoint — the same API you can call directly with your own key for production workloads.
Get your free API key at snapshot-api-production-1374.up.railway.app or try the visual diff tool now.