Is PNG compression lossless?
You can choose Lossless PNG to keep exact pixels (OxiPNG only optimizes the deflate stream and palette). Leave it off for Smart PNG, which quantizes colors with libimagequant for much smaller files — visually near-identical for UI / screenshots / logos but not pixel-perfect.
Why is my compressed PNG larger than the original?
It shouldn't happen here — we automatically fall back to the original file if our re-encode comes out larger (common with already-optimized PNGs like iOS screenshots). You'll see Saved 0% in that case instead of a negative percentage.
Can I convert PNG to WebP for even smaller files?
Yes. Use the Auto format mode (which prefers WebP/AVIF) or visit the dedicated PNG → WebP page. WebP supports transparency too.
Are my images uploaded to your server?
No. All images are processed locally in your browser using JavaScript and WebAssembly. Your files never leave your device, and we have no infrastructure that could receive them.
Can I compress multiple images?
Yes. You can drop a batch of images (or an entire folder) and download the compressed results as a single ZIP file with the original folder structure preserved.
Which formats are supported?
JPG, PNG, WebP and AVIF are supported when available in your browser. The Auto mode picks the smallest modern format your browser can encode.
Can I compress images to a specific size?
Yes. Use the
Compress to KB tool to target 100KB, 200KB, 500KB, 1MB or any custom size.
Do I need an account?
No. There is no signup, no login, and no payment. The tool works as soon as the page loads.