max-image-preview is a robots rule that sets the largest size in which Google may show an image from a page as a preview. It is set in the robots meta tag or the X-Robots-Tag header and applies to Google Search, Google Images, Discover, and Assistant.
At a glance
- Type
- Google robots rule (meta tag, X-Robots-Tag)
- Affects
- size of the image preview for a page
- Values
- none, standard, large
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What values does max-image-preview accept?
none: no image preview.standard: a default-size preview may be shown.large: a larger preview, up to the width of the viewport, may be shown.
Without the rule, Google may show a preview of the default size. The rule applies to the whole page and cannot be set for single images. It does not apply where a publisher has separately granted Google permission to use the content, for example through a licensing agreement.
| Rule | Where it's set | What it controls in Google Search | Effect on AI Overviews and AI Mode |
|---|---|---|---|
nosnippet | whole page (robots meta tag or X-Robots-Tag) | no text snippet or video preview; a static image thumbnail may still appear | content isn't used as direct input for AI Overviews and AI Mode |
max-snippet:[number] | whole page | caps the text snippet at that many characters; 0 equals nosnippet, -1 lets Google choose the length | limits how much content may be used as direct input for AI Overviews and AI Mode |
data-nosnippet | single text section (attribute on span, div or section) | the marked text isn't used in the snippet | listed by Google as a control for limiting content in AI features in Search |
max-image-preview:[none|standard|large] (this term) | whole page | maximum size of the image preview; without it, a default-size preview may be shown | Google only lists web search, Google Images, Discover and Assistant here, no AI features |
noimageindex | whole page | images on this page aren't indexed | no statement from Google |
unavailable_after: [date] | whole page | the page stops appearing in search results after that date; Googlebot then crawls the URL much less often | no separate statement from Google |
indexifembedded | whole page, only together with noindex | content may be indexed when embedded in another page through an iframe or similar tag | no statement from Google |
noindex (for comparison) | whole page | page doesn't appear in search results | listed by Google as a control for AI features; a link in AI Overviews or AI Mode requires an indexed page |
noarchive | whole page | no longer used by Google and ignored; the cached link it controlled no longer exists | none (Google ignores the rule) |
According to Google, a page can only be shown as a link in AI Overviews or AI Mode if it's indexed and eligible to be shown with a snippet. All rules only work if crawlers are allowed to fetch the page. When rules conflict, the more restrictive one applies. For AI training and grounding in some of Google's other systems, Google points to Google-Extended. Sources: Google Search Central: Robots meta tag, data-nosnippet, and X-Robots-Tag specifications (last updated 2026-03-24); Google Search Central: AI features and your website (last updated 2025-12-10). Last checked: .
Why does it matter for Discover?
Google’s Discover documentation lists max-image-preview:large (or AMP) as the way to allow large images and recommends images at least 1,200 px wide. A page that sets none or standard limits the size Google may show there.
WordPress has added max-image-preview:large to the robots tag by default since version 5.7. A filter removes it.
Example
<meta name="robots" content="max-image-preview:large">
Several rules can be combined in one tag:
<meta name="robots" content="index, follow, max-image-preview:large">
Common mistakes
- Setting
noneon a template and then wondering why no image appears for the page in Discover. - Assuming the rule picks the image. Google chooses it automatically; the rule only caps the size.
Sources
- Robots meta tag, data-nosnippet, and X-Robots-Tag specifications – Google Search Centraldevelopers.google.com
- Get on Google Discover – Google Search Centraldevelopers.google.com
- Robots API and max-image-preview in WordPress 5.7 – WordPress Coremake.wordpress.org
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