How Google Built a Better Way to Store and Send Photos Online

Google has shared the story of how it created a new image format called JPEG XL — a way to store and send photos that is more efficient than the standard JPEG format used for decades. The format was officially recognized as an international standard (ISO/IEC 18181) after years of research and experimentation.

The journey started when Google's engineers asked a simple question: could they make JPEG files smaller without losing quality. They built two experimental tools — Guetzli and Brunsli — that pushed the limits of what JPEG could do. Then they combined what they learned into a new experimental format called PIK, which eventually became part of JPEG XL.

Starting with What Worked, Then Building Something Better

Google began by trying to squeeze more efficiency out of the JPEG format that billions of devices already understood. Guetzli used tricks borrowed from how human eyes actually perceive images to compress files while keeping them looking good. Brunsli explored smarter ways to encode the compressed data itself.

The engineers then combined the best ideas from these experiments into PIK. They later merged PIK with techniques from another research project (called FUIF, from a company called Cloudinary) to create the final JPEG XL standard. This pattern — where different competing research efforts eventually merge — has happened before. When the internet moved from GIF to PNG format in the late 1990s, multiple companies were experimenting with different compression methods before settling on one standard that everyone could agree on.

What Makes JPEG XL Different

JPEG XL can make image files about 60 percent smaller than ordinary JPEG files while looking equally good to your eye. It also handles things JPEG cannot: animations, transparency, and images with a wider range of brightness (what photographers call HDR). It works both ways too — you can compress files smaller or keep them lossless, with perfect quality intact.

Importantly, JPEG XL was designed so that regular computers could encode and decode it without needing special chips or hardware. This matters because when past image formats required expensive specialized equipment, companies were slower to adopt them.

Google also released a tool called Jpegli that borrowed some of the smart compression techniques from JPEG XL. It can make ordinary JPEG files about 35 percent smaller while keeping the quality high — a useful stepping stone for people who cannot switch to JPEG XL right away.

Who Has Adopted It, and What Stands in the Way

JPEG XL is now an official standard with freely available reference software. Google tested it inside the company on its own image storage and delivery systems to make sure it actually worked well in the real world.

The broader context here is that JPEG XL is the first major image format to become an international standard since WebP was introduced over a decade ago. It was built to solve real problems facing websites today — making files smaller so they load faster, and ensuring images look good on phones, tablets, and computers.

However, adoption has hit a familiar stumbling block. Google decided not to include JPEG XL support in its Chrome web browser, which disappointed some people in the tech community who believed the company should have backed its own standard. This highlights a pattern we have seen before: even if a format is technically superior, it only succeeds if the major web browsers actually support it. The adoption of earlier formats like WebP and AVIF took years, and in some cases remains incomplete.

The good news is that JPEG XL can convert existing JPEG files to the new format without re-doing all the original compression work. This gradual pathway means companies with millions of older image files do not have to start over from scratch — a practical feature that could speed up real-world adoption.

Looking Ahead

The path from Guetzli through PIK to JPEG XL shows how open source research can lead to better standards. By releasing each experimental tool publicly, Google created a foundation of shared knowledge before finalizing the standard.

Whether JPEG XL becomes widely used depends mostly on decisions that are not purely technical. Browser makers need to support it, websites need to adopt it, and image tools need to work with it. The next year or so will probably reveal whether JPEG XL gains enough momentum to become common, or whether it stays a "technically better option that most people do not actually use" — a fate that has befallen other superior formats in the past.

The early signs from big technology companies and renewed conversations with browser makers will tell us which path it takes.