As a test, I have a set of 36 old MS paint Drawings, originally drawn on Windows 98SE, originally saved in bitmap format with a total size of 53.4 MB.
Transcoded to PNG format using FFmpeg and the highest -compression_level of 100, this same set of images takes up 403.8 kB.
Transcoded to -lossless WebP format using FFmpeg and libwebp with the maximum -quality value of 100 and maximum -compression_level of 6, the set of images takes up 174.8 kB.
Transcoded to lossless JPEG XL format using cjxl in the highest compression settings, the 36 images only takes up 126.6 kB.
Given the computing power required to decode JPEG XL images and their limited support, it may not make sense to use JPEG XL for non-archival purposes, but lossless WebP is an excellent middle-ground, achieving over 2x the compression level of PNG.
Lossless WebP has also been supported by all major web browsers since September 2022, when Apple finally added full support for lossless and animated WebP images. It really doesn't make sense to still be using PNG, unless you're targeting really out-of-date Mac or iOS devices. Having drawings and illustrations be 50% smaller (versus PNG) is huge!
I was left feeling like the next time we adopt a format that tries to do everything, it should actually do everything just as well or better than its predecessors. Lo and behold, JPEG XL is probably the first format which actually achieves this, covering all kinds of pictures you can think of and doing a pretty good job on all of them. So for the first time, I feel like the format has actually earned its place in the ecosystem, rather than just being some megacorporation’s personal favourite.
Of course, this point of view is emotional more than rational. Technically, WebP is a sensible choice, so I don’t mean to discourage anyone from using it today.
But I’m sure there are some that will say 64k of RAM is all anyone will ever need!
Even if it cannot, getting the same quality as 'classic' JPEG in fewer bits is still useful. So you have:
* better quality in the same number of bits
* same quality in fewer bits
Things in these categories have colorful packaging with spot colors, metallic inks, coatings, as well as store displays with carefully designed lighting. The added cost is justified because it increases sales. It makes sense to carry that over online.
WebP and AVIF and HEIC had similar advantages but also some disadvantages (honestly chief disadvantage to WebP in my humble opinion was that nothing except web browsers -- to this day -- seem to support it!).
Another important point in its favor is that JPEG XL is designed as a royalty‑free, open standard, and Google provides a perpetual, worldwide, royalty‑free patent license for its reference implementation.
Avoiding JXL (once the rollout is sufficiently complete) seems, to me, like still shipping (non-animated) .GIF files where .PNG is better and smaller.
Which I think it might be one of the reasons why Instagram still uses JPG for their images. The rule of thumb is that if your product is picture quality sensitive (like photos in IG) then use JPG, if not then WebP is fine since the compression is higher.
PNG/JPEG have strong support (nearly everywhere). I think of them almost as the modern TIFF - relatively simple, and almost everything supports one or both of them (few to no issues).
JXL may eventually get there (that indeed seems to be its goal), but for now I wouldn't drop e.g. PNG or JPEG support in favor of JXL now.
And arguably, perhaps never drop support; its such a prevalent format, even if all software (prevalent or otherwise) supports the format in 10 years, there will be such a huge stockpile of JPEG/PNG that something will need to be used to read/convert.
TIFF is not simple at all. There is a joke that it stands for “Thousands of Incompatible File Formats”.
Even if JXL is superior in every single way, it doesn't make sense to throw out a perfectly functional graphics package and design language for a marginal bump in capability.
For me now, its marginal.
For a past customer, not at all. That customer really cared about delivering image-heavy pages quickly. There was a fairly big difference in customer perception at a timing threshold.
Meanwhile, there's a lot of modern music that takes full advantage of quality gear, but is basically unlistenable on bad speakers.
There's nothing wrong with either approach, but if you're not trying to raise the bar why not just stick with the lowest common denominator?
Dean Martin recorded his records to sound good on low-end tween girl 1960's record players. My wife has one, and his stuff sounds great on it.
My wife also has two very high-end modern record players. Dean's old records sound like crap on that.
Master the media for the method.
[0]: https://github.com/dropbox/lepton And Lepton is dead.
JPEG XL is marketed as a high end format for photographers and already has support in most editing software.
The bees and reindeer visiting my web site will be very happy to see UV images.