Built on the AV1 video codec, and the smallest of the widely-supported image formats by a clear margin - frequently half the size of a JPG that looks the same. It handles transparency and HDR. Being new is its only real drawback: plenty of software still won't open one.

Every conversion below runs in this page, on your own machine. Nothing is uploaded, there is no queue, and there is no account to make. Pick a target format, or just drop an AVIF file above and choose afterwards.