JPEG XL Format Guide: The Future of Image Compression

The Format Designed to Replace Everything

JPEG XL (file extension .jxl) is an ambitious image format developed by the Joint Photographic Experts Group -- the same organization behind the original JPEG. Unlike WebP (created by Google) or AVIF (derived from AV1 video), JPEG XL was purpose-built as a universal image format meant to replace JPEG, PNG, and GIF in a single specification.

The format offers a remarkable combination of features: lossless recompression of existing JPEG files, progressive decoding for fast previews, HDR and wide color gamut support, lossless and lossy modes, animation, and compression efficiency that matches or exceeds AVIF in many scenarios.

Despite its technical excellence, JPEG XL has had a turbulent journey through the browser ecosystem. This guide explains what makes the format special, where browser support stands in 2026, and how to start using it today.

Core Features of JPEG XL

Lossless JPEG Recompression

This is JPEG XL's most unique feature and the strongest argument for its adoption. JPEG XL can take an existing JPEG file and recompress it losslessly, reducing file size by approximately 20% while maintaining bit-for-bit identical reconstruction of the original JPEG.

This means:

• No quality loss whatsoever -- the original JPEG can be perfectly recreated
• A 5 MB JPEG becomes roughly a 4 MB JXL
• Every JPEG on the internet could save 20% storage and bandwidth with zero risk
• The conversion is fully reversible

No other format can do this. WebP and AVIF require re-encoding from the source, which always introduces some change even in "lossless" mode.

Progressive Decoding

JPEG XL supports sophisticated progressive decoding that delivers usable previews much faster than competing formats:

This is particularly valuable for large images on slow connections. Users see a recognizable preview almost immediately, which progressively sharpens as more data arrives. AVIF, by comparison, requires most of the file to be downloaded before any meaningful preview appears.

HDR and Wide Color Gamut

JPEG XL natively supports:

• HDR (High Dynamic Range) -- Up to 32-bit floating-point per channel
• Wide color gamut -- Display P3, Rec. 2020, and custom ICC profiles
• Perceptual quantization (PQ) -- The HDR transfer function used in HDR10 content
• Hybrid Log-Gamma (HLG) -- The HDR transfer function used in broadcast

As HDR displays become standard on phones, tablets, and monitors, JPEG XL is positioned to be the format for HDR photography and content delivery.

Compression Efficiency

JPEG XL achieves excellent compression in both lossy and lossless modes:

At high quality settings where artifacts must be invisible, JPEG XL consistently matches or slightly outperforms AVIF. At aggressive compression levels, AVIF sometimes has an edge. The difference is often within 5%, making other factors (like progressive decode and browser support) more decisive.

For a detailed head-to-head comparison with AVIF and WebP, read our in-depth AVIF vs WebP vs JPEG XL comparison.

Additional Features

Beyond the headline capabilities, JPEG XL includes:

• Animation -- Replaces GIF and animated WebP/AVIF with better compression and quality
• Alpha channel -- Full transparency support (8-bit or higher)
• Layers -- Multiple layers within a single file, useful for composites
• Depth maps -- 3D depth information for computational photography
• EXIF, XMP, IPTC metadata -- Full metadata support
• Tiles -- Large images can be decoded in parallel tiles
• Responsive images -- Multiple resolutions encoded in a single file

Browser Support in 2026

JPEG XL's browser support story has been complicated. Here is where things stand:

The most significant event in JPEG XL's history was Google's decision to remove JXL support from Chrome in February 2023, citing insufficient ecosystem interest. This was controversial, particularly since Google has a competing format (WebP) and controls the AV1 codec that underlies AVIF.

Despite Chrome's absence, JPEG XL has gained ground through Safari and Firefox adoption. Apple's commitment to the format across Safari, iOS, and macOS gives it a substantial user base.

Practical Impact

With roughly 28% of global browser traffic supporting JPEG XL natively and 65% not supporting it, you cannot use JXL as your sole image format. However, you can use it as a progressive enhancement alongside JPEG or WebP fallbacks.

How to Use JPEG XL Today

Using the <picture> Element

The standard approach is to serve JPEG XL to supporting browsers with fallbacks:

<picture>
  <source srcset="photo.jxl" type="image/jxl" />
  <source srcset="photo.avif" type="image/avif" />
  <source srcset="photo.webp" type="image/webp" />
  <img src="photo.jpg" alt="Description" width="800" height="600" />
</picture>

The browser evaluates sources in order and uses the first format it supports. This gives you:

1. JPEG XL for Safari and Firefox users
2. AVIF for Chrome users (with AVIF support)
3. WebP as a secondary modern fallback
4. JPEG as the universal safety net

Content Negotiation with CDN

If your site uses a CDN like Cloudflare, Fastly, or AWS CloudFront, you can use the Accept header for automatic format negotiation:

# Client sends:
Accept: image/jxl, image/avif, image/webp, image/*

# Server responds with the best supported format

Cloudflare's Image Resizing and Polish features can automatically serve JPEG XL to supporting browsers without any HTML changes.

Converting to JPEG XL

Using cjxl (Reference Encoder)

# Lossy conversion (quality 1-100, distance 0-15)
cjxl input.jpg output.jxl --quality 85

# Lossless JPEG recompression
cjxl input.jpg output.jxl --lossless_jpeg

# Lossless from PNG
cjxl input.png output.jxl --quality 100

Using ImageMagick (7.1+)

magick input.jpg -quality 85 output.jxl

Using ConvertIntoMP4

Upload your images to the image converter and select JPEG XL as the output format. Batch conversion is supported for processing entire image libraries.

JPEG XL vs AVIF vs WebP: Detailed Comparison

Encoding and Decoding Speed

One of JPEG XL's practical advantages is speed. JPEG XL encoding is significantly faster than AVIF:

AVIF's slow encoding speed is a meaningful operational cost for sites processing millions of images. JPEG XL's speed advantage makes it more practical for real-time image processing pipelines.

Use Cases Where JPEG XL Excels

Photography Websites

JPEG XL's progressive decoding is ideal for photography portfolios where large, high-resolution images are the primary content. Users see a preview instantly while the full image loads.

Archival and Storage

The lossless JPEG recompression feature means photo archives can save 20% storage without any conversion risk. This is particularly valuable for stock photo libraries, news organizations, and museums with millions of JPEG files.

HDR Content Delivery

As HDR displays proliferate, JPEG XL is the most natural format for delivering HDR photographs. It supports the full range of HDR transfer functions and wide color gamuts natively.

E-Commerce

Product images benefit from JPEG XL's combination of excellent compression and progressive loading. Faster image loads directly correlate with higher conversion rates.

Print-to-Digital Workflows

JPEG XL supports CMYK color space and high bit depth, making it suitable for workflows that bridge print and digital delivery -- unlike WebP and AVIF, which are strictly RGB.

Creating JPEG XL Images: Best Practices

For Photographs (Lossy)

cjxl input.jpg output.jxl --quality 80 --effort 7

• Quality 75-85 is the sweet spot for web delivery
• Effort 7-9 for best compression (slower encoding)
• Effort 3-5 for fast encoding (slightly larger files)

For Graphics and Screenshots (Lossless)

cjxl input.png output.jxl --quality 100

Lossless mode preserves every pixel exactly, similar to PNG but with much smaller file sizes.

For Existing JPEG Archives (Lossless Recompression)

cjxl input.jpg output.jxl --lossless_jpeg

This is the safest conversion you can make. The original JPEG is perfectly recoverable:

djxl output.jxl restored.jpg
# restored.jpg is byte-identical to input.jpg

Batch Conversion

for file in *.jpg; do
  cjxl "$file" "${file%.jpg}.jxl" --quality 80 --effort 7
done

For larger batch operations, see our batch processing guide for parallel processing strategies.

The Future of JPEG XL

Despite the Chrome setback, JPEG XL's future is cautiously optimistic:

1. ISO standardization -- JPEG XL is an ISO standard (ISO/IEC 18181), giving it institutional permanence
2. Apple's commitment -- Full support in Safari, iOS, macOS, and Apple's photo pipeline
3. Firefox support -- Mozilla's adoption validates the format independently of Apple
4. Growing library support -- libvips, ImageMagick, Sharp, and other major libraries support JXL
5. Industry adoption -- Adobe, Facebook (Meta), and other companies have expressed support
6. Chrome reversal possible -- Community pressure continues, and Google may reconsider as the ecosystem grows

The most likely near-term scenario is that JPEG XL becomes the preferred format for Apple's ecosystem and professional photography, while AVIF and WebP continue to dominate on Chromium-based browsers. The <picture> element makes serving all formats painless.

Should You Adopt JPEG XL Now?

Adopt if:

• You serve a significant Safari/Firefox audience
• You manage large JPEG archives and want 20% storage savings
• You need HDR image delivery
• You want progressive loading for large images
• You are building a photography platform

Wait if:

• Your audience is predominantly Chrome on Android
• You have limited engineering resources for multi-format pipelines
• WebP/AVIF already meet your performance targets

The Pragmatic Approach

Implement JPEG XL as a progressive enhancement:

1. Generate JXL versions alongside your existing JPEG/WebP/AVIF files
2. Use <picture> elements or CDN-based content negotiation
3. Monitor format adoption in your analytics
4. Enjoy the benefits for Safari and Firefox users today while waiting for broader support

For more on understanding how compression works across formats, explore our guide on lossless vs lossy compression. And if you are optimizing your entire image pipeline, our article on the best image format for web and SEO provides a comprehensive decision framework.

Use ConvertIntoMP4's image converter and image compressor to experiment with JPEG XL conversion and see the file size savings for yourself. The format may not be universal yet, but for the browsers that support it, the results are impressive.