Google Images and Discover previews don't currently support JPEG XL images, Google's John Mueller said on October 15, 2026. That matters to any site tempted by the fact that Chrome and Firefox now render the format: if an image only exists as JPEG XL, Google won't use it in those places.
What we know
- What Google said: John Mueller, a Search Advocate at Google, posted on Bluesky on October 15 that JPEG XL isn't currently supported in Google Images or in Discover previews, and linked the official format documentation.
- The official list: Google's image SEO guide, last updated March 2, 2026, says Search supports images in BMP, GIF, JPEG, PNG, WebP, SVG and AVIF when referenced in the `src` attribute of an `img` element. JPEG XL isn't listed.
- The fallback: the same guide recommends always providing a fallback URL in `src` when using `picture` or `srcset`, because some browsers and crawlers don't understand those attributes.
- What Mueller added, per Search Engine Journal: serving JPEG XL inside a `picture` element works with any search engine, because that element contains a regular `img` with its own format.
- Browsers are moving: the Chrome blog announced on October 6 that Chrome 155 includes JPEG XL decoding, using a decoder written in Rust. Firefox 158, released October 13, supports it too. Safari has displayed it since 2023.
- No timeline: neither Mueller's post nor the guide gives a date for Google Images or Discover support. The Search Central changelog has no JPEG XL entry as of October 21.
What changes and what doesn't
Nothing changes on Google's side: the format list is the one the guide has carried since March. What's new is the context. With Chrome and Firefox rendering JPEG XL since October, a plugin, CDN or theme can easily start serving it, and Mueller's note makes clear that, for now, it won't reach Google Images or Discover. Google's Discover guidance asks for images at least 1,200 pixels wide and a large image set through `og:image` or structured data, but it doesn't list formats.
How to tell if it affects you
- Check which format your images use. Open one of your pages in Chrome, press F12, go to the Network tab, filter by "Img" and reload. The Type column shows whether you're serving `jxl`, `webp`, `avif` or `jpeg`.
- Check whether the format depends on the browser. Some CDNs and image-optimization plugins pick a format based on what each browser says it accepts. If that's your setup, use the live test in Search Console's URL Inspection tool to see which resources Google loads on that page.
- If you use JPEG XL, always keep a fallback. Inside `picture`, put `<source type="image/jxl" srcset="photo.jxl">` first and then `<img src="photo.webp" alt="…">`, with the `img` in one of the formats on Google's list.
- Look after your Discover image. The one in `og:image` or in structured data should use a supported format and be at least 1,200 pixels wide.
- Don't replace your originals. If a plugin offers to swap your JPEG or PNG files for JPEG XL, don't turn it on unless it keeps the fallback.
Related: Google Discover's SDF Filter: How It Drops Stale Content
Sources
- John Mueller (Google), Bluesky, October 15, 2026
- Google Search Central, "Image SEO best practices", last updated March 2, 2026
- Google Search Central, "Get on Discover"
- Chrome for Developers, JPEG XL in Chrome, October 6, 2026
- Firefox 158 release notes, October 13, 2026
- Search Engine Journal, Matt G. Southern, October 21, 2026
Updates: if Google adds JPEG XL to its supported formats, it will be noted here with a link.