Add avif images to default known static file MIME types

Is there an existing issue for this?

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Is your feature request related to a problem? Please describe the problem.

When developing web applications, the size of images is always a factor. Therefore I decided to use the avif file format. When running my web application (Angular + WebApi) with Kestrel, I have to manually add the MIME type to the FileExtensionContentTypeProvider otherwise the static file isn’t served.

Describe the solution you’d like

Please add the extension (.avif) and the MIME type (image/avif) to the dictionary in FileExtensionContentTypeProvider. I can open a PR if wanted.

Additional context

In 2019 the specifications for the avif image format have been released. Meanwhile the format is well supported for example by Chrome, Firefox, Windows, Linux and Android. It is a good candidate for being a successor of jpeg, png and webp also with regard to the open licence.

[blowdart]

I’m going to disagree here @adityamandaleeka. Windows itself supports it, as does php, android, chrome and edge. We should add it, along with HEIC/HEIF.

The usage of these types is more common than a bunch of the office formats we listed when we inherited the list from IIS, or the now dead silverlight ones 😃

[carlin-q-scott]

I’d like to add that avif files are significantly smaller than jpg of similar resolution. I switched over to using them to greatly improve my LCP metric with Google to improve my site page rank. Just swapping out a header background jpg with an avif saved me almost 2 seconds of load time on the LCP test for mobile Chrome. This file format should be gaining widespread adoption soon.

I don’t think it’s a good idea to have devs tear their hair out trying to figure out why an image asset is returning 404 despite having all the file properties set correctly. I didn’t even know that an asset in the wwwroot folder or subfolders could return a 404 until I found this issue.