PNG Compressor
Reduce PNG file size in your browser — drag and drop, tune the quality, see before/after sizes, then download. Nothing leaves your device.
What this PNG compressor does
This tool reduces PNG file sizes by re-encoding the image in your browser using the built-in HTML5 Canvas API. You can keep the file as PNG, or convert it to JPEG or WebP for much smaller output. Output dimensions can also be reduced (helpful for photos that don't need full resolution).
When to use each format
- Keep PNG — when you need a transparent background or sharp graphics/screenshots. PNG is lossless; size reduction comes mainly from dimension scaling and palette quantisation.
- Convert to JPEG — best for photographs without transparency. Usually 60–80% smaller than PNG at quality 70.
- Convert to WebP — modern format, supported in all current browsers. Typically the smallest output (often 30–50% smaller than JPEG at the same visual quality).
How it works
Your PNG is decoded into a hidden Canvas element in your browser. The tool then re-encodes the canvas at your chosen quality (for lossy formats) and dimensions, producing a Blob. Nothing is sent over the network — you can verify by checking your browser's developer tools Network tab while compressing.
Tips for the best result
- If your image is a photo, switch to JPEG or WebP — you'll see a much bigger reduction than tweaking PNG quality.
- If you only need the image to display at 800px wide on a web page, reduce Max width to 1600 (2× for high-DPI screens). This often cuts size by 60% with no visible loss.
- Quality 70% is the typical sweet spot. Drop to 50% for thumbnails, 90% for hero images you'll zoom into.
FAQs
Does this upload my image to a server?
No. All processing happens locally in your browser using the Canvas API. The file never leaves your device.
Why is my PNG output only slightly smaller than the original?
PNG is lossless, so re-encoding at the same dimensions usually gives only a modest size cut. For meaningful savings, reduce dimensions or convert to JPEG/WebP.
Will transparency be preserved?
If you keep the output format as PNG or WebP, yes. JPEG does not support transparency — transparent pixels become white.
Is there a file size limit?
Soft limit of 50 MB. Browser memory is the real constraint — very large images may slow your browser. Mobile devices typically handle up to ~20 MB comfortably.
Can I compress multiple PNGs at once?
Not yet — multi-file batch is on the roadmap. For now compress one at a time.