Why Browsers Hesitate to Support JPEG XL

Despite strong community enthusiasm and compelling technical benchmarks, major web browser vendors have hesitated to enable default support for the JPEG XL image format. JPEG XL promised to revolutionize web imagery with superior compression, high dynamic range support, and lossless legacy JPEG transcoding. However, major vendors—most notably Google in the Chromium project—pushed back, citing maintenance burdens, overlapping capabilities with competing formats like AVIF and WebP, and a perceived lack of industry-wide consensus. This article explains the technical, strategic, and ecosystem factors that caused browser vendors to stall default JPEG XL adoption.

Competing Standards and the Push for AVIF

A primary driver behind the hesitation was the industry's prior commitment to AVIF (AV1 Image File Format). Backed by the Alliance for Open Media (AOMedia)—a consortium that includes Google, Mozilla, Microsoft, and other tech giants—AVIF was engineered alongside the AV1 video codec.

Because browser engines were already integrating AV1 video decoders, adding AVIF support required relatively little additional overhead. Browser vendors viewed AVIF as a strategic, royalty-free standard that unified video and image delivery. Introducing JPEG XL, a format developed outside the AOMedia pipeline by the Joint Photographic Experts Group (JPEG committee), created an unwanted format war inside browser engines.

Codebase Complexity and Security Overhead

Adding support for an entirely new image codec is not trivial. An image decoder operates on untrusted data directly exposed to the web, making it a frequent target for memory corruption exploits and security vulnerabilities.

Every new codec introduced into a rendering engine requires continuous security auditing, fuzz testing, performance profiling, and long-term maintenance. In late 2022, Chromium engineers deprecated and subsequently removed experimental JPEG XL support, stating that the incremental benefits of the format did not justify the ongoing maintenance and attack surface expansion.

"Good Enough" Existing Formats

From the perspective of browser vendors, the modern web's image delivery problems were largely already addressed. Legacy formats like standard JPEG and PNG remain universal fallbacks, while WebP provides broad, lightweight compression. For cutting-edge compression and advanced color spaces, AVIF was deemed sufficient for the majority of consumer web use cases.

While JPEG XL technically outperforms AVIF in areas like high-resolution rendering, encoding speed, and lossless transcoding of existing JPEGs, vendors evaluated these advantages as niche benefits mostly relevant to professional photography and archiving rather than typical web browsing.

Lack of Initial Universal Consensus

For a new web standard to thrive without fragmenting the web, broad consensus among browser engines is crucial. When Google evaluated JPEG XL for Chromium, neither Mozilla (Firefox) nor Apple (WebKit/Safari) had declared firm intentions to enable it by default. Google cited this lack of broad ecosystem interest as a key justification for stepping back.

Without guaranteed cross-browser parity, developers are reluctant to deploy a format in production, which in turn reinforces browser vendors' beliefs that demand is limited to niche enthusiast communities rather than the web at large.

The Evolving Landscape

The hesitation toward JPEG XL has not remained entirely uniform. Apple shifted the narrative in late 2023 by adding support for JPEG XL across Safari, iOS, and macOS, prioritizing its advantages in high dynamic range and professional imaging pipelines. Mozilla has kept an experimental flag for the format in Firefox while tracking ecosystem adoption.

Nevertheless, because Chromium-based browsers control the majority of the desktop and mobile browsing market, Google's reluctance to reintegrate and enable JPEG XL by default remains the single largest barrier to the format becoming a universally accepted web standard.