Compare Two Images With a Before/After Slider
Put two versions of a picture on top of each other and drag a divider across to see exactly what changed: an edit, a retouch, a compression setting or a new design. Switch to side by side, or to a difference map that paints every changed pixel red and tells you how much of the image changed. Add Before and After labels and save the comparison as a single image, all in your browser.
Your image is processed by your own browser and never uploaded. Many online editors send your photo to their servers and delete it later — this one never receives it at all.
Why use Image Compare
- Draggable before/after slider, left and right or top and bottom
- Side-by-side view with both images at the same height or width
- Difference map with an adjustable tolerance and the share of changed pixels
- Editable Before and After labels
- Save the comparison as one full-resolution image
- Compared in your browser; nothing is uploaded
Popular uses
- Showing a photo edit or retouch before and after
- Checking how much quality a compression setting loses
- Spotting what changed between two versions of a design or screenshot
- Before-and-after shots for renovations, cleaning or products
Image Compare: frequently asked questions
How do I compare two images with a slider?
Drop the two images onto Image Compare. The first is Before and the second is After, stacked on top of each other with a divider you can drag. Everything left of the divider shows Before and everything right of it shows After; choose Top and bottom to move it vertically instead.
What does the difference view show?
It paints every pixel that changed between the two images in red over a faded copy of Before, and says what share of the pixels changed. The tolerance sets how big a colour change must be to count, so you can ignore the faint noise JPG compression adds.
What if the two images are different sizes?
The comparison uses Before's size. If After has the same shape it is scaled to match exactly; if its shape is different it is fitted inside Before's frame without cropping. Side by side scales After to the same height, or the same width when stacked.
Can I save the before/after comparison as an image?
Yes. Click Create Comparison Image to save the slider at its current position, the side-by-side layout or the difference map at full resolution, with your labels, as a JPG, PNG or WebP file.
Are my images uploaded?
No. Both images are compared on your device, in your browser, and the comparison image is made there too. Nothing is sent to a server.