PNG files are often much larger than necessary because they use lossless compression by default. While lossless compression preserves perfect quality, it results in larger files compared to JPEG or WebP. Compressing PNGs can dramatically reduce file sizes.
There are two approaches to PNG compression: lossless optimization (reducing file size without any quality change) and lossy compression (reducing colors and applying dithering for dramatic size reductions). ImgTools uses the lossy approach through JPEG conversion, which provides the most significant file size reduction.
For PNGs that need to stay as PNG (because they require transparency), consider reducing the color palette. A PNG-24 with millions of colors can often be converted to PNG-8 with 256 colors if the image uses flat colors, resulting in 60-80% smaller files.
With ImgTools, upload your PNG and use the Compress tab for quality-based compression (converts to JPEG), or use the Convert tab to switch to WebP format which supports transparency with much better compression than PNG.
If transparency is not needed, simply converting PNG to JPEG with ImgTools can reduce file size by 70-90% for photographic content.
All processing happens in your browser. Your PNG images are never uploaded to any server.