Compare the original file with the compressed export from the same image.
Compression quality guide
Compare Image Compression Quality
A practical guide for checking a compressed export against the original with file size, visual preview, SSIM, PSNR, RMSE, and artifact checks.
Quality92 / 100
Saved68%
SSIM0.96
PSNR34.8 dB
RGB delta3.8
Check file size saved together with visible quality, SSIM, PSNR, RMSE, and pixel change.
Inspect text, faces, gradients, and product edges because those areas reveal compression damage fast.
Start here
Check the saving and the visible tradeoff
Image compression quality comparison answers a simple question: did the smaller file keep enough visible detail?
A useful check needs both files. The original gives a clean reference, and the compressed export shows what changed after optimization.
Workflow
Compression quality review sequence
Add the original file
Use the source image, design export, or reference photo. This file gives the quality check a clean target.
Add the compressed export
Use the smaller file you plan to publish or send. A matching crop and image size make the quality comparison easier to read.
Run the quality check
Review file size saved, visual quality, confidence, SSIM, PSNR, RMSE, and pixel change.
Inspect important details
This is the key step. Zoom in on text, faces, product edges, gradients, and flat backgrounds. These areas reveal compression damage before the whole image looks wrong.
Signals
What each result tells you
SSIMSimple meaning
Compares structure: edges, shapes, layout, and main detail. A higher value usually means the compressed image still feels close to the original.
PSNRSimple meaning
Summarizes signal quality. A higher value usually means colors and brightness stayed closer.
RMSESimple meaning
Shows average error. A lower value usually means the compressed image changed less.
Mean RGB DeltaSimple meaning
Shows average color movement after compression. The tool reads red, green, and blue channels on a 0-255 scale, so a small delta means colors stayed close.
ArtifactsSimple meaning
Visible compression marks such as fuzzy text, blocky patches, color bands, edge halos, or tiny speckles.
File size saved
Visual quality
Gives a fast quality reading for the pair. A strong result usually means the compressed export stays close to the original.
SSIM
Checks structure. It helps with photos, product images, screenshots, and layouts with clear shapes.
PSNR and RMSE
Summarize signal error. Higher PSNR and lower RMSE usually mean less compression damage.
Mean RGB delta
Checks color movement on the 0-255 RGB scale. Use it to spot color shifts, brightness changes, and exports that make the image look dull or tinted.
Pixel change
Highlights areas that moved in color or brightness. Clusters around text, edges, and gradients deserve a closer look.
Examples
Where compression damage usually appears
Text and icons
Look for fuzzy letters, broken icon edges, colored halos, or small strokes that look thinner than the original.
Faces and skin
Check eyes, hair, skin texture, and soft shadows. Heavy compression can make these areas look waxy or patchy.
Product edges
Inspect labels, packaging corners, transparent edges, jewelry, fabric, and any area that must stay sharp.
Gradients and flat color
Compression can create banding, block patterns, or speckles across skies, walls, shadows, and simple backgrounds.
Decision guide
Recommendations
Good saving, clean preview
Use the compressed file if the size saving is meaningful and the important areas still look clean.
Example: a product image drops from 1.8 MB to 420 KB, and the label, edges, and shadow still look sharp.
Good saving, visible damage
Try a higher quality export or a different format if the preview shows artifacts in important areas.
Example: a WebP export saves a lot of space, but small text on the package turns soft.
Small saving, lower quality
Keep the original or export again if the file barely shrinks and visual quality drops.
Example: a photo saves only 5 percent, but skin texture and background gradients look worse.
Common checks
Results that need context
The image was resized
A resized export changes more than compression. Use matching width, height, and crop for a clearer quality reading.
The format changed
JPEG, PNG, and WebP create different artifacts. A format switch can explain a large file size change.
The image was edited too
Sharpening, color changes, retouching, or a new export preset can lower the metrics. Check the preview for the actual visible change.
The file is transparent
Transparent edges can be sensitive. Inspect logos, cutouts, stickers, and icons with alpha channels.
Try it
Open the compression quality tool
FAQ
Compression quality questions
What is a good compression quality result?
A good result has useful file size savings and a clean preview in the areas that matter. Text, faces, product edges, and gradients should still look close to the original.
Should I compare JPEG, WebP, and PNG exports?
Yes. Different formats work better for different images. JPEG often suits photos, WebP often gives strong savings, and PNG can suit graphics, transparency, and sharp edges.
Do both images need the same size?
Same width, height, and crop give the clearest result. Different sizes can still be inspected visually, but the quality reading becomes less direct.
Is my image data safe?
Yes. Image preview and quality checks run locally in your browser. No server upload is needed, so your image data stays in the active browser session.