JPEG XL is technically impressive and a definitive upgrade over JPEG, more versatile than WebP, and well-equipped for use cases beyond the Web. However, it was famously rejected from Chrome in 2023, disappointing many given its royalty-free status and compression efficiency. Recently, a JPEG XL decoder in Rust entered Firefox and Chrome, possibly signaling a reversal by major Web stakeholders to avoid reliving 2023's WebP vulnerability.

The author, a former proponent who endorsed JPEG XL for Interop 2024 and interacted with primary authors Jon Sneyers and Jyrki Alakuijala, now argues against its Web adoption. By volume, few Web use cases need lossless compression; average consumers need versatile lossy codecs. JPEG XL's lossless advantage is only roughly 11.9% smaller than lossless WebP on an unrealistic test dataset, not worth a new browser codec.

For lossy compression, modern encoders like SVT-AV1 and libaom with perceptual tuning (tune IQ) outperform JPEG XL on metrics like CVVDP and SSIMULACRA2. Aperture, Halide Compression's upcoming encoder, further widens the gap. The author concludes JPEG XL isn't competitive for lossy Web use, its only real advantage.