JPEG XL: Next-Gen Image Format Explained

What Is JPEG XL?

JPEG XL (JXL) is a modern image format designed to replace both JPEG and PNG. Developed by the Joint Photographic Experts Group — the same organization behind the original JPEG — it was finalized as an international standard (ISO/IEC 18181) in 2022. The format addresses the limitations of JPEG that have accumulated over its 30+ year lifespan while maintaining backward compatibility in a way no other modern format achieves.

The most remarkable feature of JPEG XL is lossless JPEG recompression. You can convert an existing JPEG file to JPEG XL and reduce its file size by approximately 20% without any quality loss — and then convert it back to the exact original JPEG, byte for byte. No other format offers this. It means organizations sitting on terabytes of JPEG archives can save storage space immediately without any risk to their existing files.

Beyond recompression, JPEG XL delivers genuinely better compression than its predecessors. Lossy JPEG XL files are typically 60% smaller than equivalent-quality JPEG files. Lossless JPEG XL files are 35% smaller than equivalent PNG files. These are substantial savings that translate to real bandwidth reduction for websites and applications serving large numbers of images.

Key Features of JPEG XL

Progressive decoding: JPEG XL supports progressive rendering where a low-resolution preview appears almost immediately and detail fills in as more data arrives. Unlike progressive JPEG, which renders in blocky passes, JPEG XL progressive decoding produces smooth previews from the start. This matters for large images on slow connections — users see meaningful content while the full image loads.

HDR and wide color gamut: JPEG XL natively supports high dynamic range imagery and color spaces beyond sRGB. It can encode images in the full Rec. 2100 color space with up to 32-bit floating point precision per channel. This makes it suitable for professional photography, cinema production, and HDR displays — use cases where JPEG's 8-bit sRGB limitation has been a persistent constraint.

Alpha channel and animation: Unlike JPEG, JPEG XL supports transparency (alpha channels) with the same compression efficiency as the color data. It also supports animation, positioning it as a potential replacement for animated GIFs and animated PNGs with far better compression.

Responsive images: The format includes built-in support for multiple resolutions within a single file. A server can deliver different resolution versions from the same JPEG XL file using byte range requests, without needing to store or generate separate files for each size. This simplifies responsive image delivery infrastructure.

Encoding speed: JPEG XL was designed with practical encoding speed in mind. At comparable quality settings, JPEG XL encoding is faster than AVIF and competitive with WebP. Decoding is also fast — the reference decoder was designed for single-threaded performance on mobile devices.

Browser Support Status

Browser support for JPEG XL has had a turbulent path. Chrome added experimental support behind a flag in version 91 but removed it entirely in version 110, citing insufficient ecosystem interest. Firefox supports JPEG XL since version 122 on Nightly builds. Safari added full JPEG XL support in version 17, making it available on all Apple platforms.

The Chrome team's decision to remove JPEG XL support was controversial. The format's technical advantages over WebP and AVIF are well-documented, and the decision appeared to favor Google's own WebP format. A petition to reinstate support gathered significant attention. As of now, the situation remains fluid — browser support may change as the ecosystem evolves.

For web use today, JPEG XL works reliably in Safari and can be served with fallbacks for other browsers. The <picture> element lets you list JPEG XL as the preferred format with AVIF, WebP, and JPEG fallbacks. Outside the browser, JPEG XL is supported by image viewers, editors, and operating systems — macOS, iOS, Windows (via extensions), and various Linux image viewers support it natively.

JPEG XL vs. WebP and AVIF

vs. WebP: JPEG XL compresses better than WebP at both lossy and lossless settings. JPEG XL supports HDR; WebP does not. JPEG XL handles images wider than 16,383 pixels; WebP has a hard dimension limit. JPEG XL offers lossless JPEG recompression; WebP cannot reconstruct the original JPEG. WebP's advantage is universal browser support.

vs. AVIF: AVIF and JPEG XL achieve similar compression ratios for photographic content, with AVIF sometimes edging ahead on heavily compressed images and JPEG XL performing better at high quality settings. JPEG XL encodes and decodes faster than AVIF. JPEG XL supports larger image dimensions — AVIF was designed for video frames and has practical size constraints. AVIF has broader browser support through Chrome and Firefox.

The ideal strategy for web developers is to use all three formats with progressive fallback: serve JPEG XL where supported, AVIF as first fallback, WebP as second fallback, and JPEG/PNG for legacy browsers. Build pipelines can generate all variants automatically.

Convert Images to JPEG XL

Our JPEG XL Converter lets you convert images to and from JPEG XL format directly in your browser. Upload JPEG, PNG, or WebP files and convert them to JPEG XL with adjustable quality settings. The tool shows a side-by-side comparison of file sizes and visual quality so you can find the right compression balance for your use case.

All conversion happens locally in your browser — your images are never uploaded to a server. Use it to test JPEG XL compression on your own images, evaluate the format's quality-to-size ratio, or batch-convert files for platforms that support the format.