The standard JPEG format is quite old in the computing world, dating back to 1992, but it’s still the most commonly used image file format. JPEG files are notorious for having ugly compression artifacts, especially when an image has been compressed multiple times. Nevertheless, we put up with these unsightly compression artifacts because compressed images take up much less space than images stored in lossless file formats like PNG. Images with smaller file sizes not only reduce the amount of space our devices need to store said images, but also increase the speed at which images load on the web.
In recent years, various groups have developed various alternative image file formats intended to replace the old JPEG, PNG, and GIF formats with a format that reduces file size without the noticeable artifacts and loss of fidelity resulting from older compression codecs. One of the most widely supported alternatives is WebP, which was developed directly by Google. However, Google more recently gave support to the new AFIV format, which the company helped develop.
AVIF competes more directly with Apple’s HEIC format, as AVIF and HEIC image files are generally smaller in size and higher fidelity than WebP files, but use slower codecs. Speed is essential on the web, where users expect pages to load ideally in less than the blink of an eye. So while WebP image files may look worse and be slightly larger than AVIF and HEIC files, they load much faster.
Like JPEG and PNG, JPEG XL supports progressive decoding, which WebP, AVIF, and HEIC lack. Progressive decoding means that a web page can start by loading a lower quality version of the image while waiting to fully load the image. Uploading an initial version of the image in this way can prevent images from suddenly appearing and disrupting other elements on the page.
However, despite all the apparent benefits of the JPEG XL format, Google submitted a Chromium pledge that would remove current experimental support for the new file format from its browser. The company explained this change by stating that “experimental flags and code should not remain indefinitely”. One would expect Google to simply enable JPEG XL support by default in order to remove the feature from the experimental feature list, but the company chose to do otherwise.
Google points to a lack of interest from the wider ecosystem, a lack of sufficient additional benefits over existing formats, and reduced maintenance overhead, as other reasons for its decision. Ever since Google gave its explanation, developers and engineers have flooded the thread to express their dissatisfaction with this decision and their support for the JPEG XL format. Maybe we’ll turn Google around after the public outcry, or maybe this move will mark the death of the fledgling file format, despite protests from its proponents.