Compare Images Online - Example
To show how the Compare Images tool works, we prepared two sample images: the original and a modified version where some objects are missing or have different colors. Can you spot the differences?
Original Image vs. Modified Image
Our image comparison tool quickly analyzes and compares the images, highlighting the differences in bright red. You can also change the highlight color.
After the comparison, a diff image is generated that shows exactly where the two uploaded images differ. This is useful for comparing image quality, as the tool can detect even small changes in resolution, color, or compression.
For best results, prepare the images so they have the same size and resolution. The tool supports many file types (bmp, gif, ico, jpeg, png, tga, tiff, etc.), so you can compare images in the format you prefer.
Check the Impact of Compression on Image Quality
With the Compare Images tool, you can quickly see how much detail is lost in the compressed version of your image and detect any compression artifacts.
In the example below, we compare an original JPG with a compressed version created by setting the quality to 30%. The threshold is set to 10 (1-100).
Original Image vs. Compressed Image
Image Comparison Result
The compression artifacts mostly affect the object edges in the image.
Data Table Information
The data shown below the generated diff image includes the comparison method used (here: Mean Absolute Error), the absolute error count for each color channel (Blue, Green, Red), and the total error count for all channels combined (All). It also shows the percentage of pixels that differ between the two images.
The error count shows how many pixels differ between the original JPG image and the compressed JPG image. A higher error count means more pixels have changed between the two images, which usually indicates lower compression quality, and vice versa.
The absolute error count for all channels is 8,809, which corresponds to a difference of 2.07% compared to the total pixel count of 426,400 (Total Pixels = Height x Width). This means the compression had a relatively small impact on overall image quality.
File Details
From this table, we see that the compressed image is 24.24 KB and the original image is 48.90 KB. Both images have the same dimensions (533 px x 800 px).
