This site is a collection of image utilities: converters, compressors, resizers and a set of inspection and batch tools, plus a favicon downloader on the front page.
How the tools work
The conversion, compression, resizing and inspection tools run in your browser using the standard canvas and file APIs. The image is decoded, redrawn with the settings you chose, and written out again as a new file that you download. The favicon downloader is the exception: it has to fetch a remote page, which a browser is not allowed to do across origins, so that request is made by this server on your behalf.
What the tools cannot do
Some things are simply outside what browser encoders can do, and we would rather say so than ship a page that pretends otherwise. Writing animated GIF files is the main example, which is why the GIF-related tools are disabled rather than fake. AVIF output depends on an encoder that only some browsers provide, and the tools tell you when yours does not have one.
Formats supported
Reading: JPG, PNG, WebP, AVIF, BMP, GIF and SVG. Writing: PNG, JPG, WebP, BMP and, where the browser supports it, AVIF.