PNG Compressor
Compress PNG files online and keep transparency. Each one stays a PNG with the same width and height.
Compress PNG files and keep transparency
PNG is lossless, so a PNG gets smaller in one of two ways: by using fewer colours, or by packing the same pixels more tightly. This PNG compressor does the first by default, which is what makes screenshots, logos and icons much smaller, and does only the second when you tick Lossless.
Transparent and semi-transparent pixels keep their transparency in both modes, and the width and height never change. Drop several PNGs at once, up to 40 MB each. A PNG that is already as small as it gets comes back unchanged.
Fewer colours or lossless
Fewer colours (default)
- Picks the best palette of up to 256 colours for the image, or fewer if you set Maximum colors lower
- Saves the PNG with one byte per pixel instead of three or four
- Biggest savings on screenshots, UI, charts, logos and icons
- Colours change slightly; smooth gradients and photos can show banding
Lossless
- Every pixel stays exactly the same
- The data is re-packed at the strongest compression level, and an alpha channel that is fully opaque is dropped
- Smaller savings, often none on a PNG an editor already optimized
- The choice for print files, pixel art and assets you hand over
Choosing the colours well is called quantization; how image quantization works shows why a flat graphic loses almost nothing with it while a photo does.
How many colours to keep
Maximum colors takes 16 to 256. A starting point by content:
| Content | Maximum colors | Why |
|---|---|---|
| Screenshots, UI, charts | 256 | Text and anti-aliased edges need the in-between shades. |
| Logos and icons | 64 to 128 | A few brand colours plus their edges fit easily. |
| Simple flat graphics | 16 to 32 | Few colours to begin with, so little changes. |
| Photos or smooth gradients | Lossless, or another format | A palette shows banding; JPG or WebP is far smaller for photos. |
When PNG is the wrong format
A photo saved as PNG keeps every pixel of something that never needed it, so it stays large even after compression. If the picture has no transparency, the JPG compressor makes it far smaller. Keep PNG for transparency, sharp text and flat graphics; for the web, WebP handles both photos and transparency.
How to reduce PNG size
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Drop your PNGs
Add one or several PNG files, up to 40 MB each.
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Pick colours or lossless
Keep Maximum colors at 256 or lower it for a smaller file, or tick Lossless to keep every pixel.
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Compress and download
Click Compress PNG, check the before and after size of each file, and download them.
PNG compressor questions
No. Fully and partly transparent pixels keep their transparency in both modes, so soft shadows and anti-aliased edges still blend into any background.
Yes, slightly: reducing to 256 colours changes some pixel values, though on graphics the difference is rarely visible. The result is still a normal PNG. Tick Lossless if no pixel may change.
It probably uses few colours already, or was optimized before. A PNG that cannot shrink comes back unchanged. If it is a photo, the JPG compressor will do far more.
No. Width and height stay the same; only the file gets smaller.
Not on this page, which takes PNG only. The image compressor accepts mixed formats in one batch.