Compare Images Online Free
Compare two images with slider, side by side, overlay, and pixel difference modes. Analyze file size and dimension changes instantly.
Before / Original
Drop image here or click to select
After / Modified
Drop image here or click to select
All processing happens in your browser. Your images never leave your device.
How to Compare Images
Upload Two Images
Upload your "before" image on the left and your "after" image on the right. Drag and drop or click to browse. Supports JPG, PNG, WebP, GIF.
Choose Comparison Mode
Select from Slider, Side by Side, Overlay, or Difference mode. Each mode offers a unique way to visualize changes between images.
Analyze the Results
View file size differences, dimension comparisons, and pixel-level changes. Use the stats bar for a quick overview of the comparison.
Frequently Asked Questions About Image Comparison
What image formats are supported for comparison?
You can compare images in all common formats including JPG, PNG, WebP, GIF, BMP, and SVG. Both images can be in different formats - for example, you can compare a JPG original with a WebP compressed version.
Do my images need to be the same size?
No, you can compare images of different sizes. The tool will display both images and note any dimension differences in the stats bar. However, for the most accurate pixel-level comparison using the Difference mode, images with matching dimensions work best.
What does the Difference mode show?
The Difference mode performs a pixel-by-pixel comparison of the two images and highlights any areas where the pixels differ in red. Unchanged areas appear as semi-transparent. This is especially useful for detecting subtle edits or compression artifacts.
Are my images uploaded to a server?
No. All image processing happens entirely in your browser using client-side JavaScript. Your images never leave your device. When you close or refresh the page, all image data is removed from memory.
Can I compare more than two images at once?
This tool is designed for comparing exactly two images at a time. If you need to compare multiple images, you can load different pairs sequentially. Use the Swap button to quickly reverse the before/after order.
Image Comparison Use Cases
Quality Comparison
Compare original and compressed images to evaluate quality loss. See exactly how compression affects your images before committing to settings.
Compression Testing
Test different compression levels and formats to find the optimal balance between file size and visual quality for your images.
Filter Preview
Compare images before and after applying filters, effects, or color adjustments to evaluate the visual impact of your edits.
Version Control
Track visual changes across different versions of design assets, logos, or graphics to ensure consistency and progress.
A/B Testing
Compare design variants side by side to make informed decisions about which version performs better visually and communicates more effectively.
Retouching Review
Review photo retouching work by comparing original and edited images. Verify that edits look natural and meet your expectations.
Ready to Compare Your Images?
Upload two images and compare them instantly with our powerful comparison tool. Free, fast, and private.