Compress PNG Online — Free, No Upload
Shrink PNG files in your browser while keeping transparency. Colours are reduced intelligently so the file gets smaller without a visible change.
or drag and drop here — up to 25 files at once
Your files are processed on your device and are never uploaded.
How to compress a PNG online
- 1
Add your PNG files
Drag and drop up to 25 PNG images onto the box above, or tap to browse your device.
- 2
Choose the colour count
Fewer colours give a smaller file. 128 is a safe default; drop to 64 for flat graphics and logos.
- 3
Compress and download
Press Compress PNG, then download each image or the whole batch as a ZIP. Transparency is preserved.
Why use this tool
Files never leave your device
Everything runs inside your browser. Nothing is uploaded, stored or seen by anyone but you.
No signup, no watermark
No account, no email, no branding stamped on your output. Free with no daily limit.
Instant — no upload wait
Because there is no round trip to a server, results appear as fast as your device can work.
Works on your phone
Built mobile-first, so you can do this from a phone browser without installing anything.
Why your PNG is so large
PNG stores photographic detail very inefficiently, which is why a screenshot or an exported graphic can balloon to several megabytes. If the image is mostly flat colour — a logo, an icon, a chart, a UI screenshot — colour reduction shrinks it dramatically because those images use far fewer real colours than their 24-bit depth allows for.
If the PNG is actually a photograph saved in the wrong format, no PNG compressor will help much. Convert it to JPG or WebP instead, where the same picture routinely drops from megabytes to a couple of hundred kilobytes.
Frequently asked questions
- How does PNG compression work if PNG is lossless?
- A PNG re-saved at full colour depth barely shrinks, because there is no quality to discard. The real lever is the number of distinct colours: reducing a 24-bit image to a few hundred carefully chosen colours makes each row far more repetitive, which is exactly what PNG's internal compression rewards. This tool uses median-cut colour reduction to do that with no visible change on most graphics.
- Is transparency kept?
- Yes. Only the colour of opaque pixels is adjusted — transparent and semi-transparent areas are left exactly as they were, so logos and stickers keep their see-through background.
- Are my PNG files uploaded anywhere?
- No. Everything runs inside your browser using a Web Worker. Your files are processed on your own device and never transmitted to a server.
- When should I use JPG instead?
- If the image is a photograph and does not need transparency, JPG or WebP will almost always be far smaller than any PNG. Keep PNG for logos, icons, screenshots of text and anything with a transparent background.
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