Understanding PNG Compression
PNG (Portable Network Graphics) was designed as a lossless image format, meaning no quality is lost during compression. However, this often results in larger file sizes compared to lossy formats like JPEG.
SmallBytes uses OxiPNG, an advanced PNG optimizer written in Rust, to achieve maximum compression without quality loss. For even smaller files, you can enable lossy compression which reduces colors and applies additional optimization techniques.
PNG Compression Techniques
- Color palette reduction - Reducing the number of colors in the image's palette
- Bit depth optimization - Using the minimum bit depth needed for the colors present
- Filter optimization - Choosing the best compression filters for each row
- DEFLATE compression - Applying maximum compression to the filtered data
When to Use PNG
PNG is the best choice for:
- Graphics with transparency - Logos, icons, and overlays that need transparent backgrounds
- Images with text - Screenshots, diagrams, and graphics with sharp text
- Graphics with flat colors - Illustrations, charts, and simple graphics
- Images requiring lossless quality - When any quality loss is unacceptable
PNG vs Other Formats
Choosing the right format depends on your needs:
- PNG vs JPEG - Use PNG for transparency and sharp edges, JPEG for photos
- PNG vs WebP - WebP offers smaller files but has older browser compatibility concerns
- PNG vs GIF - PNG supports more colors and better transparency than GIF