How the Image Compressor Works
DocDox Image Compressor reduces the file size of JPG, PNG, and WebP images using browser-image-compression, a JavaScript library that applies intelligent compression algorithms entirely within your browser. Your photos never leave your device — compression happens locally on your CPU with no server involvement.
Three quality presets give you quick access to common compression levels: High (minimal compression, maximum visual quality), Balanced (the optimal trade-off for most web images), and Small File (aggressive compression for size-critical use). A fine-tune slider lets you set a target file size in KB for precise control. Before and after statistics show you exactly how much compression was achieved in both file size and percentage reduction.
PNG files are additionally optimized by reducing the color palette where possible. The compression algorithms work by reducing redundant color data, optimizing encoding, and in some cases slightly reducing resolution while maintaining visual clarity at normal viewing distances.
Will compression visibly reduce my image quality?
At High and Balanced settings, compression is usually imperceptible to the human eye at normal viewing sizes. Aggressive settings may introduce visible artifacts.
Does this work on PNG files with transparent backgrounds?
Yes. PNG transparency is preserved through the compression process.
Is there a maximum image size?
No server-imposed limit. Very large images (over 20MB) may take a few seconds to process depending on your device.