Compress PNG
Lossless PNG compression. Reduce file size while keeping every pixel.
This tool re-encodes PNG files losslessly: it rewrites the image with more efficient compression so the file gets smaller while every pixel stays exactly identical to the original. The work happens entirely in your browser, so screenshots, logos, and diagrams never upload anywhere. What comes out is byte-for-byte the same picture — just packed more tightly.
Because it's lossless, there's no quality slider and no artifacts to worry about. It's the right choice when you need to keep transparency, sharp text, or precise colors intact but still want a leaner file for the web or for sharing.
Drop image here or click to browse
Output will always be PNG (lossless)
🔒 100% Browser-Based
Your image is processed entirely in your browser. Nothing is uploaded. Verify in DevTools → Network tab — zero outbound traffic with file content.
About Compress PNG
Losslessly re-encode PNG images to cut file size 30–70% without changing a single pixel. Best for logos, screenshots, and graphics with limited colors. Runs in your browser with nothing uploaded.
How to use the Compress PNG
- 1
Drop in your PNG
Add a PNG screenshot, logo, icon, or diagram. It's decoded and re-encoded locally — the file never leaves your device.
- 2
Let it re-encode losslessly
The tool rebuilds the PNG with optimized compression. No settings to tweak; the pixels stay identical by definition.
- 3
Check the size savings
Compare the original and optimized file sizes. Flat-color graphics often shrink a lot; busy, photographic PNGs shrink less.
- 4
Download the smaller PNG
Save the result. Transparency, color accuracy, and every pixel are preserved exactly — it's the same image in a tighter container.
What lossless PNG optimization can and can't do
Lossless re-encoding finds a more efficient way to store the same pixels — better filtering and stronger deflate compression — without changing a single one. The savings depend entirely on the image's content. Graphics with large flat areas and few colors (logos, icons, UI screenshots) can shrink 20–50% because that data compresses well. Photographs saved as PNG barely budge, because every pixel is slightly different and there's little redundancy to exploit. If a "PNG" is really a photo, lossless optimization won't make it small — converting it to JPG or WebP will, at the cost of being lossy.
Transparency stays perfectly intact
PNG stores an alpha channel — per-pixel transparency — and lossless optimization preserves it completely. A logo with a transparent background, an icon with soft anti-aliased edges, or a cutout with feathered shadows all come out identical, just smaller. This is exactly why PNG matters: JPEG can't hold transparency at all, and converting a transparent PNG to JPEG fills those areas with a solid color. If your image needs to sit cleanly on any background — a watermark, a sticker, a UI asset — keep it PNG and optimize it losslessly rather than converting to a format that flattens the alpha channel.
Quick tips
- ✓If your PNG is actually a photograph, lossless re-encoding won't shrink it much — convert to JPG or WebP for real savings, accepting that those are lossy.
- ✓Reducing the color palette (e.g., to 256 colors) can dramatically shrink flat graphics, but that's a lossy step — use it only when the image has few distinct colors.
- ✓WebP supports both transparency and stronger compression than PNG, so it's often a smaller lossless alternative when your destination supports it.
- ✓Crop out empty margins before optimizing; fewer pixels means a smaller file even with lossless encoding.
- ✓For UI work, keep one optimized PNG master — since it's lossless you can re-export from it endlessly with no degradation.
Frequently asked questions
How is lossless PNG compression possible?
PNG encoders have many parameter choices. Most tools pick fast defaults; re-encoding finds a smaller representation of the exact same pixel data.
Should I use PNG or JPG for photos?
JPG. PNG photos are huge — convert photographic content to JPG or WebP for far smaller files.
Will transparency be preserved?
Yes. PNG transparency is kept intact through compression.
Will lossless compression change how my image looks?
Not at all. Lossless means every pixel — including transparency and exact colors — is preserved byte-for-byte. The image looks identical; only the file size changes. There are no artifacts to inspect for.
Why did my PNG only shrink a little?
PNG already has good built-in compression, and photographic or highly detailed images leave little redundancy to squeeze out losslessly. Flat, few-color graphics shrink the most. For big savings on a detailed image, you'd need a lossy format.
Is an optimized PNG still a normal PNG?
Yes. The output is a fully standard PNG that opens everywhere the original did — browsers, editors, and apps all read it normally. It's the same format, just re-encoded more efficiently.