Compress PNG
Make PNG files smaller without losing a pixel. Lossless optimisation, right in your browser.
Drop images here
PNG
Make PNG files smaller without losing a pixel. Transparency, sharp text and flat colour are all preserved exactly.
How to compress a PNG
- Add your PNG files.
- Pick an optimisation effort — Balanced is a good default.
- Click Compress.
- Download the results individually or as a ZIP.
How lossless PNG optimisation works
The file is re-encoded with OxiPNG, which finds the most efficient way to store the same pixels: better filtering, tighter compression and no wasted metadata. The output is bit-for-bit identical in appearance.
Screenshots, icons and diagrams often drop 20–50%. Photographic PNGs save far less — for those, converting to JPG or WebP is the bigger win.
Everything happens in your browser using your device's own processing power. Your images are never uploaded to PrepImages, and nothing is stored after you close the tab.
When to keep PNG and when to convert
Keep PNG when you need transparency or crisp edges (logos, UI, line art). Convert to JPG or WebP when it's a photograph and the file size matters more than a perfectly lossless copy.
Frequently asked questions
Does compressing a PNG lose quality?
No. PNG optimisation is lossless — it removes redundant data and re-packs the file, so the output is pixel-for-pixel identical to the original.
How much can a PNG shrink?
Screenshots, logos and flat graphics often drop 20–50%. Photographic PNGs save less; for those, converting to JPG or WebP saves far more.
Is transparency preserved?
Yes. The alpha channel is kept intact.