What it does
Pngcrush is a command-line PNG optimizer that tries compression levels and filter methods and can edit ancillary chunks.
Use the command-line optimizer to try PNG filter and compression choices, with ancillary-chunk controls when metadata needs deliberate treatment. Removing a colour profile or gamma information can change how another application interprets the image, so choose those options for the intended delivery copy. The original project permits fee-free use, modification and redistribution under its embedded licence. It also distinguishes Apple's modified pngcrush, which can produce CgBI streams; do not assume the two tools have identical behaviour.
Strengths
- PNG filter and compression optimization
- Ancillary-chunk controls
Best for
- Preparing PNG files with deliberate metadata choices
Sources
- PNGCRUSH (Oct 26, 2026)
- Pngcrush source licence and Apple-modified variant distinction (Oct 26, 2026)