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Comment by Grimeton | Hacker News Reader

Avif.

Especially for animated images. Comparing webp or avif sizes to gif is easily a factor of five to ten when animated.

Author here: I'm also very much looking forward to using AVIF (and also JPEG XL), but it's another tooling question. I'm really hoping that Pixelmator Pro (now owned by Apple) will support them both soon. Photoshop (which I've recently dumped) supports WebP and AVIF, but not through the "Save for Web" or "Export As" flows. Having a nice export flow where you can easily compare compression vs. quality levels is really important to me, and I suspect to many others.

Google is no longer actively working or supporting JPEG XL.

Are you sure? They just blogged about supporting it in Chrome with their Google developed jxl implmention in Rust.

They're bringing it back. Chrome 155 onwards will support it.

https://developer.chrome.com/blog/jpeg-xl-in-chrome

Besides VMAF Netflix also released an image comparing framework back in 2020. Might be worth a look: https://netflixtechblog.com/avif-for-next-generation-image-c...

Since all modern browsers support AVIF, I'd skip WEBP and just use AVIF (possibly with a fallback for JPG/PNG).

Everytime I compared AVIF to WEBP there was basically zero size or visual difference and as far as I know AVIF is slower to encode and decode. And I'm not sure yet whether .avif files can be opened natively on Windows, Linux and MacOS on the default image viewers. I think I installed some kind of plugin via the Windows Store at some point to make that work, hard to tell now.

Odd, what are you using to create your avif's? I've done a bunch of work with them and the AVIF's were almost always significantly smaller than webp at equal or better quality.

Encoding is a pain, to be sure; I ended up creating a workflow where my source would save things as PNG files (giant, but lossless) then running a avifenc (https://github.com/AOMediaCodec/libavif) to produce the avif, and trashing the PNG.

Decoding though, all browsers have support, it's great.

> and trashing the PNG.

I don't delete my original source images, in case if I want to change the encoder parameters later, or if a newer encoder version improves quality.

When it comes to animations, is there much of a reason to use avif over webm? I suppose an avif fits into CSS and <img> without further code changes, but that's about it as far as I can think.

An AVIF and a WebM + AV1 is basically identical file-size wise, but you can zoom in on an AVIF so for actual animated images it wins on that front.

i think alpha channel is a reason, but i agree, just use webm

> I suppose an avif fits into CSS and <img> without further code changes

Which is HUGE since it allows you to embed them wherever you can embed images. I'm still mad that browser vendors didn't just allow silent looping videos in <img> tags instead of giving us these animated image formats with weirdly gimped non-keyframe compression.

I just switched to AVIF after several years of using WebP. Main reason for me is HDR support, but the smaller encoding is nice. Just beware of lossless AVIF, that's a trap.

In GIMP, when you try to save as a "lossless" AVIF, it will add a lossy colorspace conversion step (to 8 bit YCbCr) unless you specifically specify otherwise. And lossless AVIF always loses to lossless WEBP.

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