In short. Google's max-image-preview rule permits no image preview, a default preview, or a larger preview, subject to separately permitted uses.

Definition: As of October 2026, max-image-preview is Google's page-level robots rule for setting the maximum image preview size in search results. Its accepted values are none, standard, and large.

Key facts

Google's robots meta tag specification allows large previews up to the width of the viewport, the visible browser area.
Google's image SEO documentation describes image preview selection as completely automated.
Google's AI features documentation requires a page to be indexed and eligible for a search snippet to appear as a supporting link in AI Overviews or AI Mode.

What does each value allow?

The robots specification defines none as suppressing image previews, standard as permitting a default preview, and large as permitting a larger preview. Without the rule, Google may show a default-sized preview. These are size permissions; large permits the larger format.

How is the rule added to a page?

Google's specification places the robots meta tag in the HTML <head>. This example permits the default preview size:

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

An X-Robots-Tag HTTP response header can carry the same rule:

X-Robots-Tag: max-image-preview:standard

The limit has exceptions for separately permitted uses, including in-page structured data and licensing agreements. Google must be allowed to crawl the page to read its rule.

How does Google choose the image?

Google's image SEO guide describes metadata that can influence which image its automated selection uses. The og:image meta tag identifies a preferred image URL. The primaryImageOfPage property in schema.org structured data provides another way to identify that image.

The same guide recommends a representative image relevant to the page, high resolution where possible, and avoiding extreme aspect ratios. It also explains that Google finds images through the src attribute of an HTML img element and excludes CSS images from indexing. Preview size permission operates alongside these image selection and indexing mechanisms.

How can the implementation be checked?

Google's AI features guide recommends the URL Inspection tool in Search Console to examine the HTML Googlebot receives and check that preview controls are visible. After a change, Google needs time to recrawl and process the page.

For controlling information shown in AI features, the guide names nosnippet, data-nosnippet, max-snippet, and noindex. Its eligibility requirement for supporting links remains an indexed page eligible for a search snippet.

FAQ

Does max-image-preview set the text summary length?

Google's snippet guide defines a snippet as the description or summary part of a search result. You can set its maximum length with max-snippet, or exclude selected page text with data-nosnippet.

Where can I configure the tag in a CMS?

The same snippet guide explains that a content management system may provide a search engine settings page or another mechanism for adding meta tags. You can consult its instructions for modifying the page's HTML <head>.

Sources

Check how a page reads to answer engines. Open the GEO score analyzer