Optimising your Wix site thumbnail and preview image in Google search results

Search engines display thumbnail images alongside certain result listings, especially on mobile. A sharp, relevant preview image makes your listing visually dominant and measurably increases the likelihood of a click. This lesson covers how to steer which images get selected and how to maximise their impact.

How Preview Images Are Selected

The thumbnail selection process is automated. The algorithm evaluates every image on your page, weighing factors like dimensions, visual quality, topical relevance to the surrounding text, and prominence in the layout. Testing consistently shows that the largest, highest-quality image positioned near the top of the page is the most likely candidate. You cannot hand-pick the thumbnail directly, but you can stack the deck in your favour through image optimisation and the right meta directives.

Controlling Preview Size with max-image-preview

The max-image-preview robots directive sets an upper limit on how large a thumbnail the search engine is permitted to display for your page. It accepts three values:

• none: Suppresses image previews entirely for the page
• standard: Allows a small, default-sized thumbnail
• large: Permits a full-width preview that spans the result card

For almost every page on your site, "large" is the correct choice. Bigger thumbnails command more visual real estate, particularly on mobile where they significantly boost tap-through rates.

Configuring the Directive on Your Pages

Setting image preview permissions

• Open the page in your editor
• Access the SEO settings through the page menu
• Switch to the Advanced tab
• Find the robots meta tag options
• Set max-image-preview to "large"
• For a site-wide default, apply the same setting through the SEO configuration in your Dashboard for each page type
• Publish the changes

Making Your Images More Selectable

Give the algorithm strong candidates to choose from by following these practices:

• Place a high-resolution hero image (minimum 1200 pixels wide) at the top of every key page
• Choose images that visually communicate the page topic at a glance, not generic stock patterns
• Write descriptive, keyword-informed alt text for every image on the page
• Set an Open Graph og:image tag to explicitly nominate your preferred visual for sharing and potential thumbnail use
• Compress images for fast loading while preserving visual sharpness, using WebP for the best balance of file size and quality

The Role of Open Graph Images

Although og:image tags are designed for social media link previews, they also serve as a signal to search engines about which image you consider the primary visual identity of the page. Setting a dedicated og:image for each page, sized at a minimum of 1200 by 630 pixels, gives you influence over both social sharing cards and search result thumbnails.

Configuring Open Graph images

• Open the page SEO settings in the editor
• Navigate to the Social Share tab
• Upload or select the image you want as the og:image
• Ensure it is at least 1200 by 630 pixels and clearly represents the page content
• Preview the social card to confirm the image renders correctly
• Save and publish

Ongoing Thumbnail Monitoring

Essential Resources

• Google Search Console: Monitor how thumbnails and preview images appear in search results
• Facebook Sharing Debugger: Preview and debug Open Graph image tags used for thumbnails
• PageSpeed Insights: Optimise image loading performance and Core Web Vitals
• Wix SEO Help Centre: Official Wix documentation on social image and preview settings

Search your key pages on a mobile device periodically to see which thumbnails are currently showing. If the algorithm selects a low-quality or irrelevant image, improve your options by adding a stronger hero image, updating the og:image, and confirming the max-image-preview directive is set to large. Changes typically take effect within a few crawl cycles.

Key Takeaways

• Set max-image-preview to "large" across all page types for maximum thumbnail visibility
• Use high-resolution, topically relevant hero images (1200px+ wide) on every important page
• Configure og:image for each page to influence both social previews and search thumbnails
• Check your actual search result thumbnails on mobile devices regularly
• The algorithm selects thumbnails automatically, but your image choices and meta settings heavily influence the outcome