PNG Compressor
Run a real lossless PNG optimizer locally. Dimensions, colors, and Alpha stay intact, and savings are reported from the actual output bytes.
Category: compression · Priority: P1
PNG only · one file · up to 25 MiB and 40 megapixels · local lossless optimization
How to compress PNG
- Choose one structurally valid, non-animated PNG.
- Run the fixed lossless OxiPNG optimization—there is no misleading quality slider.
- Verify the real size and download the PNG if useful.
True lossless PNG optimization
OxiPNG optimizes the PNG encoding without changing decoded RGBA pixels. The file remains PNG and transparency is preserved.
Smaller is not guaranteed
An already optimized PNG can remain the same size or grow slightly. PicRecast never invents savings.
Pixel integrity over ancillary metadata
Dimensions and every decoded RGBA pixel are preserved. Nonessential ancillary metadata is not promised.
Self-hosted browser codec
The OxiPNG WebAssembly asset is served by PicRecast and runs locally in the existing Worker or main-thread fallback. No image or codec request goes to a third party.
PNG compressor FAQ
Does my PNG leave the browser?
No. The image is optimized locally with a self-hosted codec.
Why is there no quality slider?
This page is lossless. A quality slider would imply pixel loss or a mode that is not implemented.
Is transparency preserved?
Yes. Browser tests compare decoded RGBA pixels, including fully and partly transparent pixels.
Will every PNG shrink?
No. Already optimized inputs may not improve; the result is labeled honestly.
Related tools
Need PNG conversion or resizing instead?