Start with quality and savings
If both are strong, the compression is probably useful. If the file is much smaller but the quality score is low, the image may be over-compressed.
Image compression quality tool
Image Compression Quality Comparison
Run an image compression quality comparison to see whether a smaller export keeps enough visible quality.
This compression quality page compares files. It does not compress images.
Browser-local comparison
Upload files for compression quality comparison
Use an existing compressed export. The compression quality tool checks file size, SSIM, PSNR, RMSE, and visible quality in your browser.
Your private data is not exposed by this tool. It stays on your device unless you choose to share it.
A
Upload the original, uncompressed, or reference image.
Drop an image here or choose a file.
Supports PNG, JPG, JPEG, and WebP.B
Upload the compressed, optimized, or exported version.
Drop an image here or choose a file.
Supports PNG, JPG, JPEG, and WebP.Quality check
Add both files
Choose the original image and the compressed export before running the check.
Compressed image quality preview
Inspect the compressed export
Add both images
Upload the original and compressed export to unlock the slider, side-by-side view, compression map, and metrics.
Compression quality metrics
SSIM, PSNR, RMSE, and pixel changes
| Metric | Value | Meaning |
|---|---|---|
| Not available | Structural similarity. Higher is closer. | |
| Not available | Technical signal similarity. Higher is closer. | |
| Not available | Average brightness error. Lower is better. | |
| Not available | Average color change per pixel. | |
| Not available | Pixels above the balanced RGB threshold. | |
| Waiting | Different dimensions reduce confidence. | |
| Waiting | Export format stayed the same. |
SSIM
SSIM checks whether the compressed image keeps the same structure as the original.
Reading the score
How to Read an Image Compression Quality Result
A compressed image is not automatically better because it is smaller. The useful question for image compression quality comparison is whether file size savings are worth the visual quality loss.
Inspect details manually
Text, product edges, faces, gradients, and small icons can show compression damage before the whole image looks bad.
Use pixel change as a map
Tiny color shifts can touch many pixels. Look for clusters around text, edges, gradients, or faces before treating the number as a problem.
Important checks
What to Watch Out For
Before trusting the score, confirm the files match and inspect the image areas that matter most.
Same size, same crop
The cleanest comparison is two files with the same width, height, and crop. If one image was resized or trimmed, compare visually first.
Other edits change the score
Sharpening, color correction, retouching, or exporting from another source can lower the metrics even when compression is not the main issue.
Check important details
Use the slider for text, product edges, faces, and smooth gradients. Those areas usually reveal bad compression before the full image does.
FAQ
Compression Quality Comparison FAQ
Short answers about compression quality scoring, file savings, and browser-local image handling.
Can this tool compress images?
No. This image compression quality comparison page checks an original image against a compressed export. It helps you decide whether the compressed image keeps enough visible quality for the file size savings.
What is a good compression quality score?
A score above 88 usually means the compressed image is visually close to the original. A score above 95 is usually near-identical. The score is most reliable when both images have the same dimensions and crop.
Why do many pixels change even when the image looks the same?
Compression can slightly shift many pixel values while preserving the visible appearance. That is why the page shows a quality preview, SSIM, PSNR, and pixel change separately.
Should I trust SSIM or PSNR more?
SSIM is usually more useful for perceived structural similarity. PSNR is a traditional technical metric for compression quality. Use both together, then inspect important areas manually.
Do the two images need to have the same size?
For the most reliable score, yes. Different dimensions usually mean the comparison includes resizing, cropping, or scaling, not just compression.
What image formats are supported?
The tool supports PNG, JPG, JPEG, and WebP.
Are my images uploaded?
Your private data is not exposed by this tool. It stays on your device unless you choose to share it.