The short answer
For web delivery today, WebP wins over JPEG XL — not on merit, but on availability. JPEG XL compresses better, recompresses JPEGs losslessly, and supports higher bit depths, yet it renders by default only in Safari. WebP works in every modern browser. Until Chromium reverses its decision to drop JPEG XL, WebP is the format you can actually ship, and JPEG XL is the one to watch.
For controlled environments — internal tools, archival pipelines, Safari-only audiences — JPEG XL's technical advantages become usable. The decision is almost entirely about where the image will be viewed.
What each format is for
WebP, released by Google in 2010, was built to replace JPEG, PNG, and GIF on the web with one broadly supported format. Its priority was a generational compression improvement that browsers would actually adopt — a goal it achieved, reaching ~97% global support.
JPEG XL, standardised by the JPEG committee in 2021 as ISO/IEC 18181, aimed higher: a single format covering lossy, lossless, HDR, high bit depth, and lossless JPEG recompression, royalty-free. Technically it succeeds. Its weakness is distribution, not design. See the JPEG XL format overview and WebP format overview.
Where JPEG XL wins
Compression efficiency
JPEG XL compresses better than WebP at equal quality, with the gap widening at high fidelity. Where WebP's lossy mode shows artefacts under scrutiny, JPEG XL's VarDCT holds detail at smaller sizes. For archival or high-quality imaging, this matters.
Lossless JPEG recompression
JPEG XL can recompress an existing JPEG roughly 20% smaller with zero quality change, and restore the byte-identical original on demand. WebP has no equivalent — converting a JPEG to WebP is a re-encode, not a reversible repack. For large JPEG archives, this is JPEG XL's signature advantage.
Bit depth and HDR
JPEG XL supports up to 32-bit-per-channel precision and HDR. WebP is limited to 8-bit. For photography and professional workflows that need wide dynamic range, JPEG XL is the more capable format.
Where WebP wins
Browser support
WebP renders in Chrome, Firefox, Safari, Edge, and Opera — about 97% of global traffic. JPEG XL was removed from Chrome in version 110 (2023) and ships by default only in Safari 17+. This single fact disqualifies JPEG XL for general web delivery today. Full coverage is in WebP Browser Support.
Tooling and ecosystem
WebP is supported by every major CMS, CDN, and image library. JPEG XL tooling exists but is sparse: limited CMS plugins, partial CDN support, and few editors that export it. Shipping WebP is routine; shipping JPEG XL is a project.
Encoding speed
WebP encodes quickly at typical settings. JPEG XL's high-effort modes can be markedly slower. For build pipelines processing thousands of images, WebP's speed is a practical advantage.
Specification at a glance
The side-by-side table above shows the key attributes. The decisive row is browser support: JPEG XL's ~20% (Safari-only) against WebP's ~97%. Every other JPEG XL advantage is moot for content a general audience must be able to view.
Recommendation
For any public website, use WebP today, with AVIF as the aggressive-compression option above it. Do not deploy JPEG XL as a primary web format while Chromium lacks support.
Use JPEG XL where you control the client or audience — Safari-only apps, internal tooling, archival storage — and especially for lossless JPEG recompression, where nothing else competes. Revisit the decision if and when Chromium restores JPEG XL support.
Further reading
- What is WebP? A Complete Guide to the WebP Image Format — the complete format overview
- JPEG XL format overview — JPEG XL's design and capabilities
- WebP vs AVIF — the two formats you can ship today
- Is AVIF Replacing WebP? Future of Web Image Formats — the format landscape
- WebP Browser Support — compatibility detail
- Convert images: JPG to WebP, PNG to WebP