About Image Compression
Image compression reduces file size by removing redundant or less important visual data. This is essential for web performance — images often account for over 50% of a web page's total size. Compressing images before uploading to your website, email, or social media saves bandwidth and improves load times.
Lossy vs. Lossless Compression
There are two fundamental approaches to image compression:
- Lossy compression (JPEG, WebP lossy) permanently discards visual information that is less perceptible to the human eye. This achieves dramatic file size reductions — typically 70-95% smaller than the original. The quality slider controls how much data is discarded. At quality 80-85, the difference from the original is nearly imperceptible to most viewers.
- Lossless compression (PNG, WebP lossless) reduces file size without losing any visual data. The compressed image is pixel-identical to the original. Compression ratios are more modest — typically 10-50% reduction. Best for screenshots, diagrams, and images where every pixel matters.
Choosing the Right Format
- JPEG: Best for photographs and complex images with many colors and gradients. Does not support transparency. Quality 80 is the sweet spot for web use.
- PNG: Best for screenshots, logos, diagrams, and images with text or sharp edges. Supports transparency. Larger file sizes than JPEG for photographs.
- WebP: Google's modern format that outperforms both JPEG and PNG. Supports lossy and lossless compression, plus transparency. 25-35% smaller than JPEG at equivalent quality. Supported by all modern browsers.
Privacy First
This tool processes images entirely in your browser using the HTML5 Canvas API. Your images are never uploaded to any server. The compression happens locally on your device, ensuring complete privacy for sensitive or personal images.