Compress PNG free — no upload
Shrink screenshots, logos and graphics directly in your browser. Transparency is kept, and your images never leave your device.
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100% local private compression. Files never leave your device.
How PNG compression works in MiniFiles
- Processed on your device. UPNG.js decodes and re-encodes the PNG inside your browser tab. The file itself is never uploaded.
- Colour quantisation. The image is rebuilt with a palette of up to 256 colours. The Quality setting (80% by default) controls how many colours are kept — lower means a smaller file.
- Same format, same size. By default the result is still a PNG with the original file name and pixel dimensions, and transparency is preserved. Pro users can convert the output to JPEG or WebP instead.
- Metadata is dropped. Text chunks, EXIF data and embedded colour profiles are not copied into the compressed file.
- No payment needed. PNG compression and the Quality setting are free. Without an account you can compress 10 files a day; a free account removes that limit.
PNG or JPEG?
Keep PNG for screenshots, user-interface images, logos, diagrams, text and anything that needs a transparent background — these have sharp edges and few colours, which is where palette compression works best.
Use JPEG for photographs. Photos have millions of colours, so a palette-based PNG either stays large or shows banding. Save the photo as JPEG and use the JPEG compressor instead. For a mix of formats, the image compressor handles PNG, JPEG, WebP and GIF together.
Curious how local compression works? Read what client-side image compression is.
Frequently asked questions
Does MiniFiles upload my PNG files?
No. PNG compression runs entirely in your browser using UPNG.js. The file is read, compressed and saved on your device — its contents are never sent to a server.
Is PNG compression lossless?
Not strictly. MiniFiles reduces the image to a smaller colour palette (colour quantisation). Graphics that already use few colours look identical; images with smooth gradients or photos can show slight banding. Raise the Quality setting to keep more colours.
How much can I compress a PNG?
It depends on the image. Screenshots, logos and flat-colour graphics usually shrink the most; photos saved as PNG shrink less and are often much smaller as JPEG.
Is transparency preserved?
Yes. The alpha channel is kept, so transparent backgrounds and soft edges stay transparent in the compressed PNG.
Does compression remove PNG metadata?
Yes. The image is re-encoded from its pixels, so text chunks, EXIF data and embedded colour profiles from the original file are not carried over.
Compress more formats
MiniFiles also supports JPEG, WebP, GIF, and PDF compression — all locally in your browser.