PNG Compressor
Reduce one PNG with true lossless optimization. Dimensions, decoded RGBA pixels, and transparency stay unchanged, and PicRecast reports the actual output bytes even when the file does not get smaller.
Choose an image
Select one supported file to preview and validate.
PNG only · one file · up to 25 MiB and 40 megapixels · local lossless optimization
Adjust settings
Choose the output that fits your task.
Preview & download
Review the real output before saving it.
Review the real output before saving it.
How to compress PNG losslessly
- 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.
Lossless compression keeps decoded pixels unchanged
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.
Can I compress PNG without losing image quality?
Yes. This page uses true lossless PNG optimization, so decoded RGBA pixels and alpha transparency remain unchanged. Nonessential metadata is not guaranteed to remain, and an already optimized PNG may not get smaller.
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.
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