Compress PNG Online — Free, No Signup
Compress PNG online without installing anything. Drop the file, pick a quality level, and download a much smaller image. PNG screenshots routinely drop by 70 to 85 percent, and the whole process runs inside your browser.
How to do it
- Drop your PNG onto the upload box.
- Choose a quality level. PNG is re-encoded to JPEG, so use the converter instead if you need to keep transparency.
- Compare the before and after sizes.
- Download the smaller file.
Why PNG files get so large
PNG is lossless: it promises that every pixel comes back exactly as it went in. To keep that promise it can only use reversible tricks — mainly predicting each pixel from its neighbours and deflating what is left over. That works brilliantly on flat colour and terribly on photographic texture. A screenshot of a code editor is mostly flat, so PNG handles it well. A screenshot containing a photo, a gradient, or a translucent blur has millions of slightly different pixel values, and PNG has no way to round them off. The file balloons, often past 5 MB for a single desktop capture.
What this tool does to a PNG
It re-encodes the image as JPEG at the quality you choose. That is a deliberate trade: you give up the lossless guarantee and the alpha channel, and in exchange the file gets several times smaller. For a screenshot going into a bug report, a chat message, or a blog post, nobody will notice the difference. A 1.5 MB PNG capture typically lands between 300 and 400 KB at quality 75, and under 200 KB at quality 50. The pixel dimensions are untouched — only the encoding changes.
When to keep PNG instead
Three cases are worth protecting. Anything with transparency, because JPEG has no alpha channel and the tool flattens it onto white. Anything with crisp text or thin interface lines, because JPEG smears ringing around hard edges and a screenshot of small type will look visibly dirty. And anything that will be edited further, since every JPEG save is another generation of loss. For those, use the format converter and target PNG or WebP — WebP in particular keeps transparency and is usually 25 to 35 percent smaller than the equivalent PNG.
Screenshots are the common case
Most people arriving here have a screenshot that a form, an email, or an upload box has rejected. The fastest fix is almost always compression rather than cropping, because the size problem is the encoding, not the content. If the screenshot came from a high-density display it is also physically enormous — a capture from a 5K monitor is around 14 megapixels. Resizing that to 1600 pixels wide before compressing gets you a file in the tens of kilobytes with no practical loss of legibility.
Limits worth knowing
Input is capped at 5 MB, which covers the large majority of PNG screenshots but not full-screen 5K captures — resize those first. Output is JPEG at the quality you select, clamped between 10 and 95. Transparency is composited onto a white background rather than black, which matches what most people expect when pasting into a document. Nothing is uploaded, so a confidential screenshot stays on your machine.
Frequently asked questions
Does the compressor keep transparency?
No. The output is JPEG, which has no alpha channel, so transparent areas are filled with white. To keep transparency, use the format converter and target PNG or WebP.
Why does my PNG shrink so much more than a JPG does?
PNG is lossless, so it stores detail JPEG is allowed to discard. Converting a lossless file to a lossy one recovers all of that headroom at once.
Will text in my screenshot still be readable?
At quality 75 and above, yes for normal interface text. Small type at quality 50 picks up visible ringing around the letters — stay at 80 or higher if the text matters.
My PNG is over 5 MB. What now?
Resize it first. A 5K screen capture is around 14 megapixels; scaling it to 1600 pixels wide loses nothing you needed and brings it well under the limit.
Is the result still a PNG?
No, it is a JPEG. The extension and the format both change. The format converter will turn it back into a PNG, though the file will grow again.
Does this work on transparent logos?
It will run, but the transparent background becomes solid white. For logos, convert to WebP instead — smaller than PNG and the alpha channel survives.