Slashdot doesn't have table support, so it's hard to do side-by-side well, but:

JPEG XL advantages:

Licensing:

JPEG XL: Fully royalty-free (Open source / Apache 2.0)
HEIC: Proprietary patent minefield (MPEG LA, Advance, Velos; royalties apply)

Legacy JPEG Migration:

JPEG XL: Lossless, reversible bitstream transcoding (~20% smaller); fast enough for real-time web servers
HEIC: Lossy re-encode only (generational quality loss; cannot reconstruct original JPEG)

Fine Detail & Textures

JPEG XL: Retains sharp text, fine lines, subtle textures, and film grain
HEIC: Video-derived coding (HEVC / X.265). Tends to smooth out high frequences and smudge grain.

Software Encoding Speed

JPEG XL: Extremely fast; highly parallelized SIMD architecture
HEIC: Exceptionally slow and computationally expensive in software

Software Decoding Speed

JPEG XL: Fast, lightweight multi-threaded CPU decoding
HEIC: Heavy CPU overhead (without using hardware acceleration)

Progressive Rendering:

JPEG XL: True progressive decode; smart saliency algorithm to focus bandwidth on critical details first.
HEIC: None; full file must be received and decoded before display

Lossless Compression
JPEG XL: Dedicated modular mode; vastly outperforms PNG and WebP
HEIC: Ill-suited; you basically have to try to do lossless compression with an inherently-lossy format

Bit Depth & HDR

JPEG XL: Native HDR; up to 32-bit floating point per channel
HEIC: Typically capped at 10-bit or 12-bit integer

Max Dimensions & Scaling

JPEG XL: Up to 1B x 1B; efficient viewport/crop loading without full decoding
HEIC: v5.2, 4096x2160; v6.2: 8192x4320; a tiling hack allows up to 16384 x 16384

Channels & Color Spaces:

JPEG XL: Arbitrary color spaces (hyperspectral); unlimited extra channels (alpha, depth, thermal, masks, CMYK, etc)
HEIC: Rigid container; limited auxiliary channels and standard video color spaces

HEIC advantages:

Rollout / acceleration:

JPEG XL: no dedicated hardware acceleration (thankfully, it's not as important because it's so much more efficient). Software adoption still rolling out.
HEIC: Hardware silicon (ASICs). Default capture format on modern iOS/Android; native capture in Sony, Canon, and Nikon cameras

Video:

JPEG XL: Supports animations (GIF/APNG replacement), with some optimizations** (it's not just a series of stills), but lacks the full set of optimizations that a proper video codec has.
HEIC: Container naively pairs full HEVC video tracks and audio with video.

** - JPEG XL can store up to 4 reference frames in a buffer, with multiple blending modes from the references (add, replace, multiply, etc); has subframe bounding boxes ("dirty rectangles") for when only part of a frame changes; invisible frames; modular deltas (differences between frames); etc. However, it lacks motion vectors (e.g. detecting a feature drifting across a scene and simply having to encode "move it" (followed by any needed deltas). So it's great for "GIFs", but if you wanted to encode a full movie, it'd be significantly larger than e.g. HEVC.

Poor poor persecuted white male. *pats head* there there, it'll be alright. Show us on the doll where she touched you and tell use how much you liked it.

I bet you leave all your front door unlocked and open at home since someone could just break a window and therefore your house will never be safe.

Yes and so should you. Why should you be forced to pay extra to someone multiple times through every piece of software you use, because they did some math?

No it begs no such question. But to answer your independent question that wasn't begged, no there's no patent encumberment in JPEGXL, it's defined as an IEC standard, and has a reference implementation free for use under the Apache 2.0 license.

Unused, and no use case for it, no pathway predicting it would become popular, and no reason to develop it further.
That changed when the PDF/A decided to adopt JPEGXL officially. Now PDF readers need to implement JPEGXL and both Chrome and Firefox include PDF readers in the browser. Their hand was forced.

Nothing has turned into a religion. Programming rust is safer than not programming in rust due to the nature of the language and how it needs to be used to create the same class of bugs. That's not religion, that's a simple verifiable fact. No one said it's "safe", they said "safer". There's a previous implementation in a language without memory safety to compare it to.

No one said that. No one said it's "safe". They said it's "safer". Memory-safety makes the whole codebase safer than not having memory safety.

Now go look up what a "comparative adjective" is so you don't say something stupid again in the future.

So you're saying if the question isn't defined before hand the result ceases existing? Not even Schrödinger could justify a comment that stupid.

That argument only works if there either isn't a statistically measurable and consistent bias, or if you assume that bias is because men just have better ideas.

Look, I use HEIC, but JPEG-XL is just better.

* Royalty-free
* Lossless transcoding of legacy JPEGs to immediately reduce their sizes by ~20% (fast enough that you can have webservers do it in realtime)
* Better fine detail / high frequency data representation for the same bitrate. HEIC was designed for video and simply is not as good at stills.
* Faster decoding
* MUCH faster compression
* True progressive decoding - and not old-school blocky progressive decoding, but using a smart algorithm that restores coarse detail (particularly focusing on parts of the image that the eyes immediately focus on) first, then progressively adding in finer detail that the eyes take more time to notice later.
* Vastly better lossless compression
* Better colour depth and native HDR (up to 32 bit per channel)
* Up to 1B x 1B pixel images (again, useful for scientific and engineering applications), with efficient loading (don't have to load and decode the whole 1B x 1B image at full resolution to view it)
* Arbitrary colour spaces - you can even use it for scientific hyperspectral imaging. You can include e.g. alpha, depth maps, thermal data, selection masks, etc etc.

It's just a better format for stills. It's annoying that it's taken this long to get support to take off (because it takes ages for most people to update their browsers), but I'm really glad that it's starting to.

I'd like to see some comparisons between power consumption for JXL and JPEG. Constant image quality, file sizes will vary, total energy consumed by the download and decoding process.

We have known about this for decades. It's called internalized sexism. Back when women where trying to get the vote, some women opposed them. They made the same arguments against it that men did.

It's understood to be largely a product of systemic sexism in our culture. It's been getting better, but it's still there. An example is how ideals of feminity were portrayed in the 1950s. The housewife, the home maker, the mother. Obedient to her husband. That's why there was so much focus on representation, so that girls didn't grow up only seeing that as the natural and proper order of things.

In the 90s there was Girl Power, and for the last 25 years we have had many, many badass action women in movies. They aren't really what we need now though. Just more competent women doing "normal" jobs, or as normal as it gets in TV shows and movies.

We have a long history of exploiting decoders. Image based malware exists, has for decades. Hell back in 2004 the Windows GDI+ library had a arbitrary code execution attack trigged by simply opening a Office document with a specific embedded JPEG image, or using Office to attempt to insert a specific JPEG image into the document. I don't think IE was affected so it wasn't a remote execution from what I recall. That's just one example. Exploiting of decoders is a thing.

The attacks often exploit standard software bugs, e.g. memory unsafe code, buffer overflows etc. In this case they are talking "safer" because they are using the Rust based library which prevents a subset of the potential bugs creating security issues.

Don't confuse your ignorance with marketing trash.

That's cool, I'm currently at an airport on a mobile connection. How long of an ethernet cable does my NAS need to reach the next continent?