Free PNG Compressor
This free tool compresses PNG images in your browser by reducing how many colors they contain, which is what actually shrinks a PNG, while keeping transparency intact.
Drop images here
PNG files — add as many as you like
Runs entirely in your browser. Your images are never uploaded to a server.
How it works
- Drop one or more PNGs onto the box above, or click to choose them.
- Lower the color count until the saving is worth it. Logos and flat graphics stay perfect at very low counts; photographs usually want 128 or more.
- Leave 'Smooth the banding' on for photographs and gradients. Turn it off for flat graphics, where it only adds noise.
- Download the image, or the whole batch as a ZIP.
Common use cases
- Shrinking large PNG screenshots for documentation or a knowledge base.
- Cutting the weight of logos and icons on a website without losing transparency.
- Getting a PNG export from a design tool down to a sensible size.
- Reducing a flat illustration to a handful of colors with no visible change at all.
- Compressing a folder of exported assets in one pass.
Frequently asked questions
- Why does this tool reduce colors instead of offering a quality slider?
- Because PNG has no quality setting. It is a lossless format, and re-saving a PNG produces a file the same size — a compressor built that way would appear to work while doing nothing. PNG file size is driven by how repetitive the data is, so reducing the number of distinct colors is the lever that genuinely shrinks it.
- How many colors should I use?
- Logos, icons, and flat illustrations often look identical at 32 or even 16 colors, with enormous savings. Screenshots usually hold up around 64 to 128. Photographs saved as PNG want 128 or more, though a photograph is nearly always better off as a JPG or WebP in the first place.
- Does it keep transparency?
- Yes. The alpha channel is left untouched, and fully transparent pixels are ignored when building the palette so they cannot waste colors on something invisible.
- What does 'Smooth the banding' do?
- With few colors, gradients turn into visible steps. This scatters the rounding error across neighbouring pixels so the eye blends it back into a smooth gradient. It adds fine noise, which usually costs a little file size — worth it on photographs and skies, unnecessary on flat graphics.
- Would WebP be smaller?
- Almost always, yes, and it supports transparency too. If the image is going on a website, converting to WebP typically beats compressing the PNG. Stay with PNG when you need it for software that will not accept anything else.
- Are my images uploaded to a server?
- No. Compression happens entirely in your own browser. The files never leave your device, and nothing is stored.