Compress Image
Make JPEG, PNG, WebP and AVIF files smaller, by quality, by target size or automatically.
Drop images here
or choose from your device. You can also paste with CtrlV.
About this tool
Interformat compresses images with the same encoders the best desktop tools use: MozJPEG for JPEG, libwebp, libavif and oxipng, compiled to WebAssembly and run on your device.
Pick a quality and compare the result side by side, set a maximum file size and let it find the best quality that fits, or use Auto, which searches for the smallest file that still measures as visually identical to your original.
PNGs can be reduced to a 256-colour palette with dithering, which usually cuts their size by 60–80% with no visible change for screenshots and graphics.
Are my images uploaded?
No. They are read and compressed inside your browser. You can switch off your internet connection and it still works.
What does Auto do?
It encodes your image at several qualities and measures each result against the original with SSIM, a standard image-similarity score. It keeps the smallest one that stays above the threshold you choose.
Why did a file get bigger?
Already well-compressed images can grow when re-encoded. With “Never make files bigger” on, Interformat keeps the original in that case.
Which format should I use?
For photos on the web, AVIF or WebP give the smallest files. JPEG opens everywhere. Keep PNG for screenshots, logos and anything with sharp edges or transparency.