Free online image tools
Free Online PNG Image Compression
Smaller PNGs, faster loads
ImageTool.app's online PNG compressor greatly reduces PNG file size with virtually no quality loss. Everything runs locally — no upload required.
Fast processing
No server upload — images are compressed right in your browser.
Privacy first
Files stay on your device. Nothing is stored, tracked, or shared.
Download freely
Grab the result instantly.
PNG compression
Lossless PNG compression
Unoptimized PNGs are often 1–2x larger than they need to be. ImgZilla analyzes the palette structure locally in your browser, removes redundant metadata and applies smart quantization to shrink file size dramatically while fully preserving transparent pixels — images are never uploaded to any server.
Alpha channel always protected
Transparent PNGs are easily wrecked by poor compressors. We make alpha handling the top priority, so transparent areas stay pristine.
Palette optimization, no banding
PNG8 quantization tends to band on gradients. We use perceptual quantization to trim the palette almost imperceptibly while keeping visible detail.
Batch-compress PNG folders
The desktop app compresses an entire Figma / Sketch export directory at once — dozens of icons in seconds.
Built for Core Web Vitals
Google's LCP penalizes oversized images. Compressed PNGs load 3–5x faster, directly improving your Lighthouse score.
Done in 2 steps
How to compress PNG
- 01
Drop in a PNG
Works with logos, UI screenshots, icons, product shots and Figma / Sketch exports — transparency detected automatically.
- 02
Download the PNG
Format and transparency unchanged, file size much smaller — no format conversion needed.
Will compression break a transparent PNG?
No. ImgZilla specifically protects the alpha channel data throughout compression, so transparency is always preserved.
How small can a PNG get?
Logos and icons typically shrink 10–20%, screenshots and photos often 20–30%, depending on image complexity.
Should photos be PNG or JPG?
Photos are better as JPG. PNG is best for images with transparency, text, sharp edges or large flat color areas.
Can I compress PNG without quality loss?
Yes. Lossless compression only removes metadata and optimizes file structure, with zero quality loss.
Download ImgZilla for faster batch compression
Want faster batch compression and stronger privacy? The ImgZilla desktop app does everything locally on your Mac — just drag and drop.
- 100% local processing — images are never uploaded
- Multi-threaded batch compression, up to 90% smaller
- Originals auto-backed up to Trash, recoverable anytime
- Compare before and after with the built-in image compare tool
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