To compress a PNG, drop your .png files into the box above, keep the Quality slider at 80% and select Compress all. The tool reduces the number of colors in each image, which shrinks the file while keeping transparent areas. Check the Savings line on each card, then download the files singly or as a ZIP.
How to compress a PNG
- Add your PNG files. Drag them onto the drop area or select Select images. You can add up to 500 files or 2 GB at a time.
- Pick a quality. The default of 80% keeps 128 colors, which suits most screenshots and logos. Move to 95% or higher for 256 colors if you see banding.
- Scale down large images (optional). Enter a Max width or Max height to make big screenshots smaller. The proportions stay the same.
- Compress and save. Select Compress all, compare the Original and Compressed sizes, then select Download on a card or Download all (ZIP).
Why PNG compression works differently from JPG
PNG is a lossless format. Every PNG is already packed with DEFLATE, the same method used in ZIP files, and the format has no quality setting you can turn down the way JPG does. Re-packing a PNG losslessly usually saves only a few percent.
The big savings come from reducing the number of colors. A full-color PNG can hold millions of colors per image, while a palette PNG stores up to 256 and refers to them by number. That is what this PNG compressor does: it builds a palette from each image's own colors and maps every pixel to it. The Quality slider sets the palette size:
| Quality slider | Colors kept | Works well for |
|---|---|---|
| 95-100% | 256 | Detailed graphics, charts, screenshots with photos in them |
| 80-94% | 128 | Most screenshots, UI images and logos |
| 60-79% | 64 | Icons, diagrams, flat illustrations |
| 40-59% | 32 | Simple logos and line art |
| 10-39% | 8-16 | Two-tone graphics and very small icons |
Can you compress a PNG without losing quality?
Strictly, no: even at 100% this tool limits the image to 256 colors, so some color information is merged. For screenshots, logos and interface graphics the result usually looks identical, because they rarely use more than a few hundred distinct colors to begin with.
Photos are different. A photo saved as PNG has smooth gradients that need thousands of shades, so a 128-color version can show visible bands in skies and skin. For photos, a lossy format is the better fit: convert with the PNG to JPG converter, or to WebP with the PNG to WebP converter if you need to keep transparency.
How to compress a PNG to under 1 MB
Start with the dimensions, because a PNG's size grows with its pixel count. A screenshot from a high-resolution laptop display can be 2880 x 1800 pixels. Setting Max width to 1920 brings it to 1920 x 1200, which removes more than half the pixels before any color reduction.
- Enter 1920 (or smaller) in Max width.
- Leave Quality at 80% and select Compress all.
- If a card still shows more than 1 MB, lower the slider to 60% and select Recompress on that card.
Keep an eye on the Savings line. A PNG that was already optimized by another tool may not get any smaller. The tool then keeps your original file, and the card says Already optimised.
Does compressing a PNG keep the transparent background?
Yes. Transparency is stored per pixel and carried into the palette, so cut-out logos, icons and stickers stay transparent after compression. Soft edges such as drop shadows keep their partial transparency too, though at very low settings the shadow may show a few visible steps.
Everything runs in your browser. The files are read from your device, compressed in memory and handed back as downloads named name-compressed.png. Nothing is uploaded.
Frequently asked questions
How do I compress a PNG file for free?
Drop the PNG into the compressor on this page and select Compress all. There's no sign-up, no watermark and no upload.
What does the quality percentage mean for a PNG?
It sets how many colors the compressed PNG may use: 256 at 95% and above, 128 from 80%, 64 from 60%, 32 from 40%, 16 from 20% and 8 below that.
Why does a card say Already optimised?
The original was probably already a small palette PNG, or it was optimized by another tool, so re-saving it would have made it bigger. The tool never gives you a larger file: it keeps the original instead. Try a lower quality setting if you still need it smaller.
Will my PNG keep its transparency?
Yes. Transparent and semi-transparent pixels are kept in the compressed file.
Should I compress a photo as PNG or convert it to JPG?
Convert it. Photos need thousands of shades, so color reduction can cause banding, while JPG or WebP shrink photos far more with less visible change.
How many PNG files can I compress at once?
Up to 500 files or 2 GB in one batch. Download them all together with Download all (ZIP).