Image Compressor with Preview - See Before & After
Compress images with a live before-and-after preview slider. Compare original and compressed quality side by side before downloading. 100% client-side, free to use.
Compressor
Compress any image with live preview and quality slider.
Quality shrinker
Shrink images without visible quality loss.
Target size
Compress to exact file sizes with preview validation.
Why preview matters before downloading
Blindly compressing images often leads to unpleasant surprises: blurry text, muddy gradients, or banding artifacts that only become obvious after upload. An image compressor with preview lets you inspect the exact visual difference before committing to the compressed file.
CompressNeo's preview feature displays a draggable comparison slider. Drag left to see the original, drag right to see the compressed version. This makes it trivial to catch quality issues and adjust settings accordingly.
How the preview workflow works
- Upload: Drop your image into the compressor. Both original and compressed versions are rendered to canvas.
- Compress: Adjust quality, format, or target size. The tool reprocesses the image in real-time.
- Compare: Use the before/after slider to inspect compression artifacts, blur, and color shifts.
- Download: Once satisfied with the preview, download the optimized file with confidence.
Use cases for preview-based compression
Designers validating screenshot compression, photographers checking photo quality at different settings, and marketers ensuring brand assets remain crisp all benefit from visible previews. The preview reduces the guesswork and eliminates the need for multiple compression cycles.
Frequently asked questions
Does the preview show the exact downloaded quality?
Yes. The preview renders the same compressed output that will be downloaded. What you see is exactly what you get.
Can I compare side by side?
Yes. The before/after slider lets you compare original and compressed images by dragging a divider across the image.
Does preview mode affect compression speed?
Minimally. The preview shares the same canvas rendering pipeline, so there is no additional server round-trip or processing delay.
Can I zoom into the preview to check details?
Yes. Open the preview in fullscreen mode to inspect fine details like text sharpness and gradient smoothness at 1:1 pixel ratio.