Visual Image Diff Slider - Online Compare Two Photos

An image diff slider lets you visually compare two pictures by dragging a handle to reveal one image over the other. It is commonly used to spot changes between an original and a modified version, perfect for photographers, designers, and developers.

Upload your original image (Image 1) and the modified version (Image 2). Use the Slider mode to drag the handle and reveal the changes. Switch to Side by Side for a split view, or Difference to see pixel‑level changes highlighted in red. You can also download the highlighted diff image.

All common image formats work, including JPEG, PNG, GIF, WebP, and BMP. The tool runs entirely in your browser, so there is no server‑side conversion.

No. Everything is processed locally on your device. Your photos never leave your computer – the tool works completely offline and respects your privacy.

Currently, the difference engine uses a fixed threshold that reliably highlights visible changes. We plan to add a sensitivity control in a future update. For now, the highlight is optimized for clear, noticeable differences.

If the two images have different dimensions or aspect ratios, the tool uses contain scaling so both fit inside the viewer without cropping. This may cause slight mismatches when comparing because the alignment is per image center. For best results, use images of the same size or crop them beforehand.

Once two images are loaded, click the “Download Diff” button. The tool automatically generates a diff image (differences shown in red) and triggers a download. No need to switch to the Difference view first.

There is no hard limit, but very large images (e.g., 50 megapixels) may slow down the difference calculation on less powerful devices. For typical photos from a camera or phone, performance stays smooth.