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About PNG Compressor Online
This tool optimises PNG images using lossless and selective lossy techniques. Lossless reduction reorganises filters and Huffman tables to encode the same pixels more efficiently; lossy reduction quantises the color palette to dramatically smaller files (especially effective for graphics with limited colors).
PNGs are often used for logos, screenshots, icons, and graphics where transparency is needed. Optimised PNGs can be 30-80% smaller than the original — significant savings for assets shipped to every visitor of a website.
The tool preserves transparency (alpha channel) by default. Lossless mode keeps the image pixel-perfect; selective lossy mode visibly reduces size but may introduce slight color banding in gradients.
How to use this tool
How to losslessly shrink a PNG's file size
Upload the PNG
Drop a `.png` file into the "Image" field. The image's pixels, transparency, and dimensions are preserved — only the encoding bytes get tighter. Output is still a fully valid PNG playable in every browser/viewer.
Press Run
Result returns `bytesIn`, `bytesOut`, `savedPercent`, and the optimised file. Savings vary wildly: large photo-like PNGs barely shrink (you should be using JPG/WebP), but icons and screenshots can drop 30–60%.
When PNG is the wrong format
PNG is lossless and best for sharp-edged graphics, screenshots, and icons. If your image is a photograph, switch to WebP (smaller AND mostly indistinguishable) or JPG. Compressing a photo as PNG is fighting the format.
If savings disappoint
PNGs from pngcrush/pngquant/oxipng already squeeze hard. If `savedPercent` is < 5%, your source is already near optimal. For deeper savings consider quantising to palette PNG (loses subtle colour gradients) or converting to WebP.