FLIF VS OptiPNG

JXL contains FLIF, one of the most efficient lossless formats. Source: 11 months ago

As for lossless image compression, FLIF is based off of a deriviative of CABAC (used by H264) called MANIAC (which I couldn't find any information for). As mentioned on the website in general it outperforms PNG at around 33% smaller files. Interestingly enough, FLIF is a predecessor to JPEG-XL which is what this post is talking about. Source: over 1 year ago

I'm a huge fan of AV1 for video, but for images JPEG-XL is simply the better codec than AVIF. If you've not actually looked closely at a comparison and are just on the side of AVIF in this debate because it's based on AV1 (and maybe you hate HEVC / HEIC), I'd urge you to look closer. Jpeg XL is pretty unrelated to Jpeg, Jpeg 2000 and Jpeg XR and instead a successor of Google Guetzli, FLIF and newer research. Source: over 1 year ago

Legally they had no choice because jpeg xl is based on flif.info and https://github.com/google/pik but the flif has LGPL license which should open source the rest.. However regardless the media group didn't really do much other than write some standard and slap their name on it. Wasn't their work. Source: over 1 year ago

No this is a niche format like FLIF was flif.info which got embedded in jpeg xl along with other image technologies. The tech behind QOI and many other things is great, and hopefully the research goes into usage in the future but it won't get mass adoption. Source: over 1 year ago

Did you compare to PNG crush and optipng? Those are what I used to use because they're easily installable Linux/brew packages. Source: about 1 year ago

Assuming your frames are PNG files, you could use a lossless optimizer like optipng to try if their size can be reduced. I prefer oxipng, which is faster and multithreaded, and seems to have more active development. Source: over 2 years ago