We need an alternative to JPEG that a) is widely supported, b) has better compression efficiency and c) has a wider feature set. We believe AV1 Image File Format (AVIF) has the potential. Using the framework we have open sourced, AVIF compression efficiency can be seen at work and compared against a whole range of image codecs that came before it.

I was a initially sceptical of AVIF – I don't like the idea that the web has to pick up the scraps left by video formats. But wow, I'm seriously impressed with the results above.

… ~50% savings compared to JPEG, and ~20% savings compared to WebP.
… can be lossy or lossless, has the ability to use an alpha channel (transparency for UI and design elements), and even has the ability to store a series of animated frames (think lightweight high-quality animated GIFs).
… one of the first image formats to support HDR color support; offering higher brightness, color bit depth, and color gamuts.