compare images online.
Compare two local images using overlays, adjustable difference thresholds, pixel error statistics and downloadable QA heatmaps.
JPG, PNG, WebP where supported • One or two source files • Processed locally
Browse files ↗How to compare images online
Visual comparison is useful for checking before-and-after edits, screenshots, product revisions and design regressions. A single shifted pixel can create a strong heatmap, so align both images to the same canvas before interpreting differences. Mean absolute error measures numerical change, while PSNR measures signal-to-error ratio.
- Upload reference and comparison image.
- Choose overlay or heatmap view, threshold and alignment adjustment.
- Inspect differences and export a heatmap and results summary.
Accuracy, privacy and limitations
Images are compared in a common raster canvas; color management and resampling may change pixel values. This is not semantic AI visual understanding.
Practical advice for a cleaner result
Always keep a copy of your source files. Compare the new image at 100% zoom, test it in the application where it will be used, and make one change at a time when a result looks unexpected. Browser memory limits depend on device and image dimensions.
compare images online FAQ
Do both images need the same dimensions?+
No. The comparison image can be scaled to the reference canvas.
Can I download differences?+
Yes. Export the heatmap as PNG and numerical summary as CSV.
Does PSNR prove two designs look identical?+
No. It is a numerical metric and should be combined with visual inspection.