max-image-preview:large: What It Does for Google Discover

max-image-preview:large is a robots meta directive that tells Google it may show a large preview of your page's image. It matters most for Google Discover, where a card with a full-width image is the difference between being noticed and being scrolled past. This guide covers what the directive does, what Google's documentation says about it and Discover, how to check whether your pages carry it, and the ways it goes missing on WordPress sites.

What the directive says

It lives in the robots meta tag in a page's <head>:

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

It takes one of three values:

Google's documentation adds that when the directive is absent, it may show an image preview of the default size. So a page without it is not hidden from anything. It is limited to the standard preview.

The directive arrived in 2019 alongside max-snippet and max-video-preview, as a way for publishers to say how much of a page may be previewed. It grants permission. It does not ask for anything, and it is not a ranking signal.

What Google says about Discover

Google's Discover guidance for publishers, as we read it in November 2026, advises including compelling, high-quality images, especially large ones, which it says are more likely to generate visits from Discover. It recommends images that are:

1. at least 1,200 pixels wide, in high resolution and a 16:9 shape, and
2. enabled by the max-image-preview:large setting, or by using AMP.

It also advises against generic images, giving a site logo as the example, and against text-heavy images, in the og:image tag and schema markup. The wording of that page changes from time to time, so read the current version before relying on a detail.

Read that carefully for what it does not say. The directive does not get a page into Discover. Eligibility comes from being indexed and meeting Discover's content policies, and whether a page is shown depends on Google matching it to a reader's interests. The directive affects how the card looks when the page is shown: with a large image, or with a small thumbnail beside the title.

That still matters. A page that meets every other recommendation but lacks the directive, or has a 600-pixel image, should expect the small card.

Check your own pages

View the source. Open a post, view the page source and search for name="robots". You are looking for max-image-preview:large in the content value.

Or from a terminal:

curl -s "https://yoursite.com/a-recent-post/" | grep -i -o '<meta name=.robots.[^>]*>'

Check for a second source. The same directives can be sent as an HTTP header, which applies even when the HTML has no tag:

curl -sI "https://yoursite.com/a-recent-post/" | grep -i "x-robots-tag"

Check what Google read. In Search Console, inspect the URL and run the live test, then view the crawled page's HTML. This catches cases where a cache or CDN serves crawlers something different from what you see.

Test a post, not the homepage. Templates differ, and Discover shows articles.

Why it goes missing on WordPress

WordPress has printed max-image-preview:large in its own robots tag since version 5.7, on any site that is not set to discourage search engines. So a plain WordPress site has it. It disappears in a few ways:

• An SEO plugin replaces the WordPress tag. Most SEO plugins print their own robots meta tag and remove the one WordPress makes. Whether the replacement includes max-image-preview:large depends on the plugin and its settings. This is the most common cause, and it is silent: nothing looks wrong in the dashboard.
• A setting says standard or none. Some plugins expose the image preview size as a setting, per site or per post type. A value chosen years ago for another reason stays in force.
• A theme prints a hard-coded robots tag. Older themes sometimes do. You then have two tags on the page.
• A header set at the server or CDN. An X-Robots-Tag rule added for PDFs or a staging site can end up applying to everything.

Google's robots meta documentation says that when robots rules conflict, the more restrictive rule applies. By that rule, two tags, one saying large and one saying standard, leave you with standard. Finding the directive once in the source is therefore not enough; make sure nothing else contradicts it.

The image has to qualify too

The directive is half of the recommendation. The other half is an image at least 1,200 pixels wide.

• Upload large originals. An 800-pixel image cannot become a 1,200-pixel one. WordPress scales down, never up.
• Set a featured image on every article. A post with no featured image leaves the choice to whatever is in the content.
• Check what your theme outputs. If the theme serves a 768-pixel version to every device, make sure the larger sizes are in the srcset, and that your og:image tag and Article schema point at the full-size file, since those are where an article states which image represents it.
• Avoid text-heavy graphics and logos. Google's guidance advises against both in the image you nominate.

When you would choose a smaller preview

Almost never for articles. The cases are narrow: a photographer or illustrator who does not want large previews of the work shown outside the site, or licensed images whose terms limit reproduction. Then standard or none on the affected pages, not the whole site, is the proportionate choice. Expect smaller cards in Discover and plainer results as the price.

Setting it in WordPress

If your source check shows the directive is missing, the fix depends on what removed it:

• With no SEO plugin, WordPress adds it for you. If it is absent, look for a theme function or a small plugin filtering wp_robots.
• With an SEO plugin, look for its robots or "advanced robots" settings and set the image preview to large, site-wide.
• In code, on a site with no SEO plugin managing the tag:

add_filter( 'wp_robots', function ( $robots ) {
	$robots['max-image-preview'] = 'large';
	return $robots;
} );

In Hydrogen SEO, version 0.0.30 and later print max-image-preview:large on every indexed page by default, together with max-snippet:-1 and max-video-preview:-1. The values are on Hydrogen SEO → Robots → Snippets & Previews, and a single post can have its own in the SEO Settings sheet. Earlier versions did not print it. The details are in snippet and preview controls.

Measure the effect

Search Console has a separate Discover performance report, which appears once a site has had enough Discover impressions. After fixing the directive, watch click-through rate there, not impressions: a larger card should earn more taps from the same number of showings. Discover traffic swings widely from week to week for reasons that have nothing to do with your markup, so compare a month with a month.

If the report does not exist for your property, the site has not had meaningful Discover exposure yet, and the directive alone will not create it. It removes one obstacle. Timely, original articles with strong images do the rest.

Summary

• max-image-preview:large permits large image previews. Without it Google may still show a default-size preview.
• Google's Discover guidance recommends images at least 1,200 pixels wide, enabled by this directive or AMP.
• WordPress adds it by default, and SEO plugins that replace the robots tag can remove it without notice.
• Check the page source and the response headers, and make sure no second tag contradicts it.

Related: the meta robots tag and Google Discover glossary entries.