Free Online Image Comparison Tool — Before & After Slider
Compare two images side by side with our free online image comparison tool. Use the interactive slider overlay to reveal differences between the original and modified versions of an image. Perfect for photographers comparing edits, designers reviewing changes, or anyone who needs to spot visual differences between two photos. Upload multiple images and freely select which two to compare. All processing happens locally in your browser.
Upload two or more images to the compare tool.
Select which image appears on the left (original) and which on the right (modified) side.
Drag the slider back and forth to compare details between the two images.
Tips for Comparing Images
- Use the swap button to quickly switch which image is on the left and right side for a different perspective.
- For best results, compare images of the same dimensions. Images with different sizes will be aligned by their top-left corner.
- The slider works with both mouse drag and touch input on mobile devices.
Frequently Asked Questions — Image Compare
Is the image comparison tool free?
Yes, completely free. No registration, no hidden charges, and no file size limits. All processing happens locally in your browser.
How does the comparison slider work?
The comparison slider shows both images in the same position. The left image is visible on the left side of the slider, and the right image on the right side. Drag the slider handle to move the dividing line and compare different parts of the images.
Can I compare images of different sizes?
Yes, the tool displays both images at their original sizes within the comparison area. If the dimensions differ, both images are independently scaled to fit the viewport while maintaining their aspect ratios.
How do I switch which images are compared?
Upload multiple images, then click 'Select as Left' and 'Select as Right' buttons on any image to choose which pair to compare. You can also use the 'Swap Sides' button to flip the left and right images.
What image formats are supported?
All common image formats are supported: JPEG, PNG, WebP, BMP, AVIF, GIF, and TIFF. If your browser can display it, you can compare it.
Is the comparison accurate?
The tool displays the actual images from your files at full resolution. There is no compression, resizing, or quality loss during the comparison process. What you see is the exact pixel data from your original files.
Can I compare more than two images?
Upload as many images as you like. You can freely choose any two from the list to compare, making it easy to cycle through different pairs without re-uploading.