Most images on the web still rely on formats designed decades ago. JPEG dates back to the early 1990s, PNG followed a few years later, and both were built for a very different internet. JPEG XL is an attempt to replace them with a single modern format that handles photographs, graphics and high-end imaging equally well.
Where the older formats struggle
Each traditional format has strengths, but also clear limits. JPEG compresses photos efficiently but produces visible artefacts at low quality and does not support transparency. PNG is lossless and handles transparency, yet its files become very large for photographs. WebP improved on both in many cases but has its own restrictions, such as limited colour depth for high dynamic range work. Web developers often juggle several formats to cover every use case.
What JPEG XL brings
- Efficient lossy compression: smaller files at comparable visual quality, according to the format's design goals.
- True lossless mode: pixel-perfect storage for graphics and archiving.
- Lossless JPEG recompression: existing JPEG files can be repacked into smaller JPEG XL files and restored to the exact original later.
- Wide colour and HDR: support for high bit depths and modern colour spaces.
- Transparency and animation: alpha channels and animated images in one format.
- Progressive decoding: a usable preview appears quickly while the rest of the image loads.
Side-by-side overview
| Format | Lossy | Lossless | Transparency | HDR |
|---|---|---|---|---|
| JPEG | Yes | No | No | Limited |
| PNG | No | Yes | Yes | Limited |
| WebP | Yes | Yes | Yes | No |
| JPEG XL | Yes | Yes | Yes | Yes |
Who benefits most
Photographers gain a format that can store high-quality, high-bit-depth images without the bulk of uncompressed files. Web developers can potentially serve smaller images that load progressively. Archives and media libraries benefit from lossless recompression of large JPEG collections, saving storage while keeping the originals recoverable.
The adoption question
A format is only useful if software can open it. Support for JPEG XL has grown in image editors, operating systems and some browsers, but it is not yet universal, and browser vendors have taken different positions over time. For websites, the practical approach is to offer JPEG XL with a fallback format so every visitor sees an image. Checking current support tables before committing is wise, because the situation continues to change.
Trying it out
The easiest way to judge the format is to convert a few of your own images and compare file sizes and quality. An online converter for/to jpegxl makes that experiment quick, and command-line tools from the reference implementation offer finer control for batch work. Testing with real content shows whether the gains justify adding JPEG XL to an existing workflow.
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Corrections are always welcome.