How it works
Formats and their options
Open one or more images and pick an output format. PNG can keep transparency or sit on a background colour. JPEG has a quality and a background colour. WebP and AVIF have a quality or a lossless switch. GIF has a colour count and a palette mode, one of which keeps transparency. BMP is 24-bit or 32-bit with alpha.
TIFF is written uncompressed, so the file is width × height × 4 bytes. ICO and ICNS hold a single icon size or every size in one file (ICO 16 to 256 px, ICNS 16 to 1024 px).
Resizing
Keep the original size, scale by a percentage, or set a custom width and height. With Keep aspect ratio on, the side you type drives the other, and each image follows its own proportions.
Batches
Each image is converted with the same settings and listed with its new pixel size and file size. Download one, or all as a ZIP; repeated names get a number so nothing is overwritten.
