Hydrogen SEO
Log inStart free
Technical

What is max-image-preview?

max-image-preview is one of the directives a page can put in its meta robots tag to control presentation, as opposed to indexing. It answers a single question: when this page appears in a result, how big may its image be?

There are three answers. none forbids an image preview, standard allows one at the default size, and large allows one as wide as the screen. A page that does not state a preference is treated by Google as allowing a default-size preview.

Updated By the Hydrogen SEO team

How it works

The directive is read per page, from the robots meta tag or from an X-Robots-Tag response header:

  • max-image-preview:none
  • max-image-preview:standard
  • max-image-preview:large

It is a permission, so it changes how a result may look and has no effect on whether the page ranks. The place it is most visible is Google Discover: Google's guidance for publishers recommends images at least 1,200 pixels wide there and lists max-image-preview:large, or AMP, as what enables large images.

If a page sends two different values, for instance one in a theme's tag and one in a plugin's, Google follows the more restrictive of the two.

Example

A news article that wants full-width cards:

html
<meta name="robots" content="index, follow, max-image-preview:large" />

A portfolio page whose photographer wants only small thumbnails shown off-site:

html
<meta name="robots" content="max-image-preview:standard" />

The same instruction for a file type with no HTML head, sent by the server:

code
X-Robots-Tag: max-image-preview:large

In WordPress

Since version 5.7, WordPress core adds max-image-preview:large to the robots tag of any site that is open to search engines. SEO plugins usually swap that tag for their own, and then the value depends on the plugin. Hydrogen SEO prints max-image-preview:large on indexed pages from version 0.0.30, with the size selectable under Robots → Snippets & Previews and for individual posts in the SEO Settings sheet; see snippet and preview controls.

Common mistakes

  • Assuming it is there. Check the page source of an article after installing or switching an SEO plugin.
  • Setting large and uploading small images. The permission is useless without an image of 1,200 pixels or more.
  • Using none to protect images. It only limits previews in results. It does not stop anyone opening the image on your page.

Common questions

Is max-image-preview a ranking factor?

No. It controls the size of the image preview a result may use. It can change how many people click a result, especially in Discover, but it is not used to rank pages.

What happens if I leave max-image-preview out?

Google may show an image preview at its default size. Google's Discover guidance lists the large value, or AMP, as what enables large images there.

Related terms