Compress PNG to under 100 KB
Squeeze a PNG under 100 KB in your browser.
Make images or PDFs smaller.
- JPG · PNG · WebP · Text · Word
- Word
- PDF · Text
This is free and always will be. Buy me a coffee
Your files are processed by your own browser and never sent to a server.
100 KB is enough PNG for a screenshot, not for a photograph
A PNG encoder throws nothing away, so the size of the file is decided by how repetitive the picture is: long runs of identical pixels collapse to almost nothing, and noise does not compress at all. A screenshot of a text-heavy page or a dialog box is mostly repetition and usually clears 100 KB at its real dimensions, untouched. A screenshot with a gradient or a photograph behind it is not, and gets scaled in steps until it fits. The dividing line is not how big the picture looks but how much of it is genuinely different from the rest of it, which is why two screenshots of the same window can differ tenfold in size.
What kind of PNG fits in 100 KB?
A screenshot at its real size, a logo, an icon, a line diagram: anything made of flat colour and hard edges, which is what PNG is actually good at. A photograph saved as PNG does not fit at anything like full size and has to be scaled down heavily to get there. The distinction is worth checking before you start, because the two cases behave so differently that the same budget is generous for one and impossible for the other.
Can I keep transparency and still hit 100 KB?
Yes, and it costs less than people expect. An alpha channel adds relatively little to a PNG of flat artwork, so a logo with a transparent background usually fits comfortably. If it does not, WebP keeps the transparency too and compresses considerably better, which makes it the better target whenever the file is going on a web page rather than into software that demands a PNG.
Why did my screenshot come back the same size?
Because it already fitted, and the tool hands back the original bytes whenever it cannot beat them. For a text-heavy screenshot under 100 KB that is the usual outcome: PNG stores long runs of identical pixels almost for free, so there is nothing left to win. The tile reporting the same size in and out reads like a failure and is the opposite of one. It does mean the file keeps whatever metadata it arrived with, because nothing was re-encoded - if removing that was the point, Clean does it without touching a pixel.
More on where 100 KB comes from, and on what compressing PNG actually does.
Should the output stay PNG?
At this budget, usually yes. A screenshot, a logo or a diagram generally clears 100 KB as PNG without being touched at all, and converting it would trade a lossless file for a lossy one to save bytes you did not need to save. Auto still tries several encoders and keeps the least damaged result, so if PNG was the wrong container for this picture the tool will tell you by handing back something else. The exception is a photograph saved as PNG, where 100 KB costs most of the pixels and WebP would hold the same picture at full size.
A different budget
The same budget for JPG. With no format in mind, compress any image to 100 KB. With no limit in mind, compress PNG.