Diff Statistics
Get a complete quantitative comparison of two images: pixel-level differences, dimensions, file sizes, perceptual hash values, and visual similarity score.
Click or drag image here
PNG, JPG, WebP, GIF
Click or drag image here
PNG, JPG, WebP, GIF
Image A
| Filename | - |
| Dimensions | - |
| File size | - |
| pHash | - |
Image B
| Filename | - |
| Dimensions | - |
| File size | - |
| pHash | - |
Comparison Metrics
Understanding the Metrics
Pixels Changed
The number and percentage of pixels whose Euclidean sRGB distance exceeds the configured tolerance. This metric is sensitive to compression, rendering engines, and font antialiasing. Use a tolerance of 3-10 to filter noise from JPEG encoding.
Perceptual Hash (pHash)
A 64-bit hash derived from the low-frequency DCT components of the image. The hash is stable under minor resizing, light compression changes, and small brightness shifts. Two identical images always produce the same hash. The hash is displayed as a 16-character hexadecimal string.
Hamming Distance
The number of bit positions where the two pHash values differ (0-64). A distance of 0 means the images are perceptually identical. Distances up to 10 typically indicate the same image saved at different quality settings or slightly different dimensions. Distances above 20 usually indicate substantially different images.
Visual Similarity
A derived percentage calculated as (64 - hammingDistance) / 64 * 100.
100% means identical pHash values. This is an approximation of human-perceived similarity
for the overall tonal and structural content of the image, not a pixel-perfect measure.