What is AVIF
An AVIF file is an image format developed by the Alliance for Open Media that reduces our images' size while maintaining quality. Experts consider it to be the next advancement in media compression. The mission of AOMedia is to develop open, royalty-free technologies for delivering multimedia content, meaning no one will have to pay for the use of the new AVIF format. AOMedia is backed by major corporations such as Netflix, Google, Facebook, Apple, or Microsoft. Presently, JPG and PNG are the most commonly used image formats on the Internet. A few years ago, WebP, developed by Google, emerged on the scene, which delivers images 30% smaller than JPG while maintaining comparable image quality. Pictures made with AVIF can be 50 percent smaller than JPG images while still maintaining the quality.
What is Instagram
Instagram is a photo and video sharing social media service developed by Kevin Systrom and Mike Krieger. Facebook acquired the service in April 2012 for approximately US$1 billion in cash and stock. Users of the application can upload media files that can be edited with filters and categorized based on hashtags and geographic location. Posts may be shared publicly or with pre-approved followers. Users can browse other users' content by categories and places and view trending content. In addition to liking photos, users can follow other users to add their content to a personal feed.
AVIF support
As of this writing, Instagram does not support the upload of WebP or AVIF files. It will display the following message when you try to upload the file: "Unable to upload. The file type is not supported. Supported file types: image/jpeg, image/png, video/mp4 and video/quicktime."

It is possible to upload JPGs and PNGs. Instagram also displays images in JPG format. It may be due to the large size of the images uploaded to Instagram. Since WebP still does not have 100% support and AVIF has 60% support, Instagram would have to serve multiple image formats to ensure that all their users' devices are supported. The amount of storage required would be huge, with more than 50 billion photos, without including resized images for different devices.