AVIF vs WebP vs JPEG XL: Choosing a Next-Gen Image Format in 2026

For most of the last decade, "use a next-gen image format" simply meant "use WebP." That advice is no longer complete. Two newer contenders — AVIF and JPEG XL — now promise even smaller files and richer features. But smaller is not automatically better when browser support, encoding cost, and tooling are on the line. Here is how the three formats actually compare in 2026, and a pragmatic strategy that lets you ship the best one to every visitor.

Meet the Contenders

All three formats exist to solve the same problem: the venerable JPEG and PNG formats were designed in the 1990s and waste enormous amounts of bandwidth by modern standards. Each newcomer attacks that waste with more sophisticated compression, but they come from very different lineages.

WebP — the established default

Developed by Google and derived from the VP8 video codec, WebP supports both lossy and lossless compression, an alpha channel for transparency, and animation. It typically produces files 25–35% smaller than equivalent JPEGs and PNGs. With well over 95% global browser support and fast, mature encoders, WebP is the format you reach for when you want a guaranteed win with zero compatibility worries.

AVIF — the compression champion

AVIF is built on the royalty-free AV1 video codec and is, frame for frame, one of the most efficient image formats available. It excels at preserving detail at very low file sizes, supports wide color gamut and HDR, and handles transparency and animation. In typical web scenarios it lands meaningfully smaller than WebP at equivalent visual quality — the gap is largest for photographic content at aggressive compression levels.

The catch is encoding cost. Squeezing an image into AVIF is computationally heavy and can be noticeably slower than WebP, which matters if you are processing thousands of images in a build pipeline. AVIF can also struggle with very fine, high-frequency detail (think sharp text inside an image), occasionally smearing it at low bitrates.

JPEG XL — the promising outsider

JPEG XL (file extension .jxl) is arguably the most technically ambitious of the three. It offers excellent compression, progressive decoding, and a genuinely clever party trick: it can losslessly transcode existing JPEGs to a roughly 20% smaller file that can be perfectly restored to the original. On paper it is a fantastic all-rounder.

Compression: What to Actually Expect

Be skeptical of any single "X% smaller" headline figure. Real-world results depend heavily on the image content, the target quality, and the specific encoder settings. As a rough mental model for typical web photography at comparable quality:

• JPEG — the baseline (100%).
• WebP — roughly 25–35% smaller than JPEG.
• AVIF — often 20–50% smaller than WebP again, with the biggest gains at low file sizes.
• JPEG XL — broadly competitive with AVIF, and uniquely strong at high-fidelity and lossless use cases.

The lesson: the right answer is workload-dependent. A hero banner that must look pristine has different needs than a thumbnail grid where raw byte count is king. Always test with your own representative images rather than trusting a generic benchmark.

The Pragmatic Strategy: Don't Choose, Layer

You do not have to bet on a single format. The HTML <picture> element lets the browser pick the first format it understands from a prioritized list. Offer AVIF first, fall back to WebP, and finally a universally supported JPEG. Every visitor automatically gets the best format their browser supports, with zero JavaScript.

<picture>
  <!-- The browser tries these in order, top to bottom -->
  <source type="image/avif" srcset="hero.avif">
  <source type="image/webp" srcset="hero.webp">

  <!-- Universal fallback for older browsers -->
  <img
    src="hero.jpg"
    alt="Sunrise over a mountain range"
    width="1200"
    height="675"
    decoding="async"
  >
</picture>

Notice that the dimensions and alt text live on the fallback <img>, which is the element that actually renders. Always include width and height here to reserve layout space and protect your Cumulative Layout Shift score.

Weighing Encoding Cost and Tooling

Format choice is also an operations decision. AVIF's slower encode time is trivial for a handful of marketing images but can dominate a pipeline that processes a large catalog on every deploy. Many teams settle on a sensible compromise: generate WebP for everything because it is fast and universal, and add AVIF for the high-traffic, high-impact images (hero banners, category headers) where the extra savings justify the encode cost.

Whatever you choose, the foundational step is the same: stop shipping raw, oversized JPEGs and PNGs. Even moving a site entirely to well-tuned WebP captures the large majority of the available savings, and you can layer AVIF on top later as a refinement.

About WebPMagic

WebPMagic is an independent project focused on image optimization and web performance. These guides are researched and edited to give developers clear, practical, and accurate information for building faster websites, with tips drawn from hands-on use of our own WebP conversion tool. Found an error or have a suggestion? Let us know via our contact page.