JPEG XL vs JPEG, WebP and PNG: Is It Ready for Websites?

JPEG XL has taken a significant step towards becoming a mainstream website image format. In October 2026, Google Chrome and Mozilla Firefox enabled native support, joining Apple’s Safari, which has supported the format since 2023.

For website owners and developers, this raises an important question: is JPEG XL now a better choice than traditional JPEG, WebP or PNG?

The short answer is that it offers some substantial advantages, but it is not yet a universal replacement for existing image formats. Its compression capabilities, support for high-quality imagery and ability to preserve existing JPEG files make it particularly interesting. However, browser compatibility, image-processing software and search engine support still matter.

Here is what has changed, how the formats compare and when switching might actually make sense.

What Is JPEG XL?

JPEG XL, commonly abbreviated to JXL, is a modern image format standardised as ISO/IEC 18181. It was developed to improve how digital images are compressed, stored and delivered, while addressing several limitations of traditional JPEG.

Despite its name, this is not simply an improved compression setting for an existing .jpg file. It is a separate image format, using the .jxl extension and image/jxl MIME type.

According to the JPEG committee’s official specification overview, it supports both lossy and lossless compression, transparency, animation, high dynamic range (HDR), wide colour gamuts and progressive image decoding.

These capabilities allow one format to handle several types of imagery that would traditionally require different file types.

What Makes JPEG XL Different From Traditional JPEG?

Traditional JPEG has remained widely used for decades because it offers a practical balance between image quality, file size and compatibility. Its limitations, however, become more noticeable when working with modern displays and demanding photographic workflows.

Better Compression Without Necessarily Sacrificing Quality

The newer format can achieve smaller files than conventional JPEG at comparable visual quality. In its October 2026 announcement, Google’s Chrome team described a compression improvement of approximately 30–50% compared with traditional JPEG.

That figure should not be interpreted as a guaranteed file-size reduction for every photograph. Actual results depend on image content, compression settings, encoder configuration and the visual quality being targeted.

Nevertheless, it represents a meaningful improvement over a technology that remains common across websites, photography libraries and business media archives.

Lossy and Lossless Compression in One Format

Traditional JPEG primarily uses lossy compression. Some image information is discarded to reduce file size, and repeatedly saving an image with lossy compression can introduce additional degradation.

JXL supports both lossy and lossless compression.

With lossless compression, the decoded image data can be reproduced without losing information. That makes it suitable for images where accurate preservation matters, not just photographs where some compression artefacts might be acceptable.

Lossless Recompression of Existing JPEG Files

One of the format’s most distinctive features is its ability to recompress compatible existing JPEG files without losing the information needed to reconstruct the original.

This is different from opening a photograph and exporting it again with a higher-quality setting.

Using reversible JPEG transcoding, an existing file can be stored more efficiently and later restored to its original JPEG bitstream. When the appropriate reconstruction information is retained, the original file can be recovered exactly.

For organisations maintaining large photographic archives, this is particularly interesting. It creates an opportunity to reduce storage requirements without permanently abandoning existing files.

HDR, Transparency and Progressive Loading

The format also supports capabilities that are missing or limited in conventional JPEG, including alpha transparency, wide colour gamuts, high bit depths and HDR imagery.

Another feature is progressive decoding. Instead of waiting for an entire image to download, a compatible decoder can display an early representation and progressively refine its detail as more image data arrives.

For large, high-resolution photographs, this can improve perceived loading behaviour. However, the benefit depends on how the file was encoded and whether the browser supports progressive rendering.

JPEG XL vs JPEG, WebP and PNG: Feature Comparison

Choosing the right image format depends on more than compression. A website may need transparent graphics, pixel-perfect screenshots, photographic quality, animation or compatibility with older browsers.

The following table compares the main capabilities of four common or emerging raster image formats.

Sources: JPEG committee, MDN image format documentation and Google’s WebP specification. Some capabilities depend on the browser or image decoder rather than the format alone.

Is JPEG XL Better Than WebP?

JXL supports a broader set of advanced imaging capabilities than WebP, particularly for HDR photography, high-bit-depth images, progressive decoding and reversible JPEG transcoding.

However, WebP remains an excellent choice for ordinary website images. It offers efficient lossy and lossless compression, transparency, animation and broad browser compatibility.

A website already using properly optimised WebP images should not assume that converting everything to another format will deliver a noticeable performance improvement.

Could It Replace PNG?

For some use cases, yes. Lossless compression and transparency support make the newer format suitable for graphics that would traditionally be stored as PNG files.

That does not mean PNG should disappear from website workflows. It remains widely supported, predictable and practical for screenshots, graphics and applications that require exact image reproduction.

SVG also remains a better choice for many logos, icons and scalable vector illustrations. Replacing those assets with a raster image format would often miss the reason they were vector graphics in the first place.

How Much Smaller Are JPEG XL Images?

Compression results are one of the strongest reasons to investigate the technology, but comparing formats requires care.

A smaller file is not automatically better if it has noticeably lower visual quality. Equally, a lossless file should not be compared directly with a heavily compressed lossy file as though both preserve the same information.

In August 2026, Mozilla published a technical comparison of modern image compression formats using example photographs and screenshots.

For one photograph of a fox, Mozilla reported the following file sizes when preserving the source image losslessly.

In that particular lossless comparison, JXL produced the smallest file.

However, Mozilla’s lossy comparison of the same photograph produced a different result. At a similar measured visual quality, AVIF required 116 KB, compared with 134 KB for its newer competitor.

This highlights an important distinction: the newer format can be particularly competitive for lossless or high-fidelity imagery, while AVIF can produce smaller files for conventional web-quality photographs.

The best choice depends on the images being compressed and the quality required. Testing representative images is more useful than relying on a single percentage from a format comparison.

Which Browsers Support JPEG XL in 2026?

Browser support was historically one of the main obstacles to adoption. That situation changed significantly in October 2026.

Google announced decoding support in Chrome 155 on 6 October 2026. Mozilla followed with the capability enabled by default in Firefox 158, released on 13 October 2026.

Safari has supported still images in this format since Safari 17, although its implementation does not support every feature.

Browser support information: Can I Use compatibility tables, Chrome for Developers and Firefox 158 developer release notes. Compatibility continues to change.

Why Microsoft Edge Matters

Microsoft Edge uses the Chromium browser engine, but that does not mean every feature introduced in Google Chrome is automatically enabled in Edge.

As of October 2026, JXL images are not supported by default in Edge 155.

This is an important reason to avoid serving the format as the only image option on a public website. A visitor using an unsupported browser must still receive something they can display.

Older browser versions and other browsers also need consideration. Support in the latest Chrome or Firefox release does not mean every visitor has updated.

Will JPEG XL Make Websites Faster?

The newer compression technology could improve website performance when it reduces the number of bytes that must be downloaded. This may be particularly useful for websites containing large photographs, extensive product galleries or high-resolution imagery.

Progressive rendering may also improve how quickly visitors can recognise an image while it is downloading.

However, choosing a newer file format is only one part of website performance.

Images still need appropriate dimensions, compression settings, responsive variants, caching and sensible loading priorities. A photograph delivered at unnecessarily large dimensions can waste bandwidth regardless of whether it is encoded as JPEG, WebP, AVIF or JXL.

Decoding performance, browser behaviour and additional processing requirements can also affect the final result.

For a wider explanation of these considerations, see Nort Labs’ guide to improving website loading times through technical optimisation.

The practical approach is to compare files at equivalent visual quality and then measure how they perform on real devices and browsers.

Does Google Search Support JPEG XL for SEO?

This is where browser compatibility and search engine support need to be treated separately.

Google Chrome can display the format, but that does not automatically mean Google Search can index those files as image search results.

According to Google Search Central’s image SEO documentation, the documented supported image formats include BMP, GIF, JPEG, PNG, WebP, SVG and AVIF.

JXL is not currently included in that documented list.

For businesses that depend on Google Images, visual product discovery or image-rich organic search results, that distinction matters.

Using a supported image format as the fallback remains sensible. Google also recommends using standard HTML image elements with descriptive alternative text so search systems can discover and understand images.

The wider relationship between imagery and discovery is covered in our article on how Google Visual Search helps people discover websites through photographs.

There is no reason to assume that adopting JPEG XL provides an SEO ranking advantage simply because it is newer. Any potential performance benefit should be measured, while image discovery and indexing requirements must still be satisfied.

How Can Websites Use JPEG XL Without Breaking Images?

Websites can provide alternative image formats using the HTML <picture> element.

This allows a browser to select a file type it understands instead of forcing every visitor to download the same format.

For example, a website could offer a JXL version first, a WebP alternative for browsers without support, and a traditional JPEG as the final fallback.

A compatible browser would select the first supported source. An unsupported browser would continue to another option rather than displaying a broken image.

The standard JPEG fallback is also useful because Google’s documented image-discovery guidance supports image URLs in the src attribute of an HTML <img> element, including when that element appears inside <picture>.

The order of the formats is not arbitrary. Browsers generally select the first compatible source, so the newer file type should only take priority over WebP or AVIF when testing shows that it is appropriate for those images.

Most websites do not need to create multiple versions manually if their existing image optimisation service or content delivery network already manages format negotiation and fallbacks. However, support for the newer codec must be confirmed rather than assumed.

Can You Use JPEG XL With WordPress?

Support in web browsers does not automatically translate into complete compatibility across WordPress hosting, media libraries, image optimisation plugins and content delivery networks.

WordPress 7.1 introduced significant improvements to client-side media processing, and JXL was among the formats explored during development and testing.

However, the WordPress 7.1 media-processing documentation describes a supported client-side MIME type set covering JPEG, PNG, GIF, WebP and AVIF. That does not establish a complete, universal JXL publishing workflow.

For a WordPress website, several separate capabilities need checking: whether an upload is accepted, whether thumbnails and responsive image sizes can be generated, whether the web server delivers the correct MIME type and whether an optimisation plugin or CDN provides fallback formats.

For websites built with Elementor, the same principles apply. Elementor displaying an HTML image element is different from the underlying WordPress installation being able to process and deliver that image format reliably.

Before changing a production image library, the full upload, processing, delivery and fallback workflow should be tested.

Should You Start Using JPEG XL on Your Website?

There are good reasons to begin evaluating the format, but that does not mean every website needs to migrate immediately.

• For ordinary business websites: well-optimised WebP, JPEG and PNG images remain practical. The newer format can be tested without replacing the existing delivery setup.
• For photography, portfolio and image-heavy websites: JXL is particularly worth investigating for high-fidelity imagery, larger photographs and progressive rendering.
• For ecommerce websites: test different codecs against existing product imagery. Compare file sizes at similar visual quality, then verify compatibility and image indexing.
• For large JPEG archives: reversible recompression may offer value independently of whether public website visitors receive JXL files.
• For websites using WordPress or a managed image CDN: confirm the entire image delivery pipeline supports the format before committing to a change.

Is JPEG XL the Future of Website Images?

The technology has moved beyond the browser-support uncertainty that previously limited its adoption. With Chrome 155 and Firefox 158 enabling it by default, and Safari already supporting still images, the format is now considerably more practical for web developers than it was only a few months ago.

Its technical advantages are real. Better compression than conventional JPEG, lossless encoding, reversible transcoding, HDR support and progressive decoding make it a useful addition to the options available to developers.

But no single format is automatically best for every image.

JPEG remains useful for compatibility. PNG remains dependable for lossless graphics. WebP offers an effective balance between compression and widespread support, while AVIF remains highly competitive for smaller photographic files.

Our recommendation is to treat JPEG XL as a format worth testing now, rather than a format every website must immediately adopt. Where it produces measurable improvements, it can be introduced alongside reliable alternatives. Where the difference is marginal, a simpler and already well-supported image workflow may still be the better decision.

For website owners, the objective is not to use the newest image format. It is to deliver images that look right, load efficiently and work reliably for the people visiting the website.