Compress PNG images without losing quality
Re-pack PNGs losslessly with OxiPNG – every pixel stays identical. Need a much smaller file? Switch the output to WebP in one click.
- No upload
- Free, no sign-up
- Whole folders
- Works offline
Drop images or a folder here
JPG, PNG, WebP, AVIF or BMP · no file limit
Processed on your device. Nothing is uploaded.
How to compress PNG files
- 1
Add your PNGs
Drop PNG files or a folder of screenshots, icons or graphics onto the tool.
- 2
Lossless optimization runs automatically
OxiPNG finds a more compact way to store exactly the same pixels. Transparency is preserved.
- 3
Want more savings? Switch to WebP
Choose WebP as the output format and click Apply for files that are typically 25–80% smaller.
- 4
Download
Download one file, a ZIP with your folder structure, or save back into the folder in Chrome and Edge.
Lossless PNG optimization, explained
PNG is a lossless format, so the quality slider does not apply to it. OxiPNG instead finds a more efficient way to store exactly the same pixels. Savings are usually 5–30%, depending on how the PNG was originally saved.
Screenshots and graphics exported from design tools often shrink the most. PNGs that were already optimized may not shrink at all – in that case Asset Compressor keeps the original.
When to convert PNG to WebP instead
If the images are going on a website, WebP keeps transparency and is typically 50–80% smaller than PNG for photos and 25–50% smaller for graphics. Every modern browser supports it.
Keep PNG when you need pixel-perfect output for further editing, or when a platform only accepts PNG.
Photos saved as PNG
PNG is a poor fit for photographs: a photo saved as PNG can be five to ten times larger than a high-quality JPEG or WebP. If your PNGs are photos without transparency, convert them to JPEG or WebP for dramatic savings.
Frequently asked questions
Why did my PNG only get a little smaller?
Lossless optimization can only remove inefficiencies in how the file is stored, not image detail. For big savings, convert to WebP or AVIF, which use much more efficient compression.
Is transparency preserved?
Yes. PNG, WebP and AVIF output all keep the alpha channel. Only JPEG output replaces transparent areas with white, because JPEG has no transparency.
Are my PNG files uploaded anywhere?
No. The OxiPNG encoder runs as WebAssembly inside your browser tab. Your files never leave your device.
Does lossless mean the pixels are identical?
Yes. Decoding the optimized PNG gives exactly the same pixels as the original. Only the way the data is packed changes.
Should I use PNG or WebP for screenshots?
For publishing on the web, lossless or high-quality WebP is usually much smaller and looks the same. Keep PNG when you need to edit the screenshot later or a platform asks for PNG.
Related tools
PNG to WebP
Turn heavy PNGs into lightweight WebP files that keep their transparency. Convert one file or a whole folder at once.
PNG to JPG
Photos saved as PNG are often huge. Convert them to JPG for dramatically smaller files that open anywhere.
Convert to AVIF
AVIF delivers the smallest files of any widely supported image format. Convert JPG, PNG or WebP to AVIF in bulk, locally on your device.
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