Did Google+ markup really control how shared URLs were cached?

What was the context of this Google recommendation?

This statement from John Mueller dates back to when Google+ still existed as a social network competing with Facebook. At that time, Google offered a proprietary markup for webmasters to control how their URLs were displayed when shared on the platform.

The system relied on specific meta tags that allowed site owners to define what content would be displayed in the preview. The objective was twofold: to enhance user experience on Google+ and to give publishers precise control over their branding during shares.

Why did Google emphasize this markup?

At that time, Google was trying to establish its social network in competition with Facebook. Controlling the appearance of shared links was a strategic imperative for the platform.

The term "caching" in the title refers to the fact that Google+ stored this information for faster display. Without proper markup, the social network would use generic or poorly formatted snippets, which harmed engagement. Thus, publishers had a vested interest in implementing these tags to maximize their click-through rates from Google+.

Does this guideline still hold any technical relevance?

No. Google+ has shut down, making this markup completely obsolete. No crawler uses it anymore today.

However, the principle remains valid: controlling how your URLs appear during social sharing is crucial. Open Graph tags (Facebook) and Twitter Cards have taken over and are now the universal standards. Every serious site must implement these metadata to ensure consistent display across networks.

• The Google+ markup was a proprietary initiative that is now abandoned
• Open Graph tags and Twitter Cards have become the essential standards
• Caching of social previews remains an active mechanism across all platforms
• Incorrect markup leads to degraded displays and measurable traffic losses
• Facebook and Twitter validators allow you to test the display before publication

Was this recommendation consistent with observed practices?

At the time of Google+, yes. Sites that implemented this proprietary markup did see their shares better formatted on the platform. However, in retrospect, it was a technical dead end.

Google asked webmasters to invest time in a non-universal standard, while the Open Graph from Facebook already existed and worked across almost all platforms. Many professionals wasted hours implementing tags that became useless overnight. [To be verified]: no study has ever shown that this Google+ markup had a direct SEO impact on the search engine itself, contrary to the rumors of that time.

What lessons can be learned from this obsolete guideline?

The first lesson: never bet everything on a single proprietary standard. Google's recommendations can become outdated if they serve temporary commercial interests rather than enduring technical needs.

The second lesson: favor multi-platform protocols. Open Graph works on Facebook, LinkedIn, Pinterest, and many others. Twitter Cards covers the X ecosystem. These two standards meet 95% of needs. Adding additional proprietary tags usually provides only marginal gains at a high maintenance cost.

Should you still care about caching social previews?

Absolutely. Each social platform caches the information it scrapes during the first share. If your Open Graph tags are misconfigured or missing, this incorrect version will remain cached for days or even weeks.

In practice, you must systematically test your URLs using Facebook and LinkedIn validators before any sharing campaign. An error in image ratio or a truncated title can halve your engagement. Platforms do not re-scrape automatically unless you manually refresh them via their debug tools.

What should you implement on your pages?

Forget about Google+ markup. Focus on two standards: Open Graph and Twitter Cards. These meta tags in the of your pages define the title, description, image, and content type for social sharing.

For Open Graph, the minimum tags include og:title, og:description, og:image, og:url, and og:type. For Twitter Cards, add twitter:card, twitter:title, twitter:description, and twitter:image. The recommended image dimensions: 1200x630 pixels for Facebook, 1200x600 for Twitter, JPG or PNG format under 8 MB.

How can you check if your markup works properly?

Use the official validators: Facebook Sharing Debugger and Twitter Card Validator. Paste your URL, inspect the displayed result, and correct any errors flagged. These tools show you exactly what users will see when a share occurs.

If you modify your tags after an initial share, you must force re-scraping using these same tools. Otherwise, the old cached version will continue to be displayed. Also, ensure your images are accessible (no robots.txt blocking) and that their URLs are absolute HTTPS, not relative.

What technical mistakes should you absolutely avoid?

The first common mistake: using too small or improperly proportioned images. Facebook will crop or reject images under 200x200 pixels. LinkedIn requires a precise ratio of 1.91:1 for optimal display.

The second mistake: duplicating tags. If both your CMS and a plugin generate Open Graph tags, you create conflicts that platforms resolve randomly. Inspect the source code to detect these duplicates. Finally, never neglect og:locale (fr_FR, en_US, etc.) which influences regional display on certain platforms.

• Implement Open Graph (og:title, og:description, og:image, og:url, og:type) on all shareable pages
• Add Twitter Cards (twitter:card, twitter:title, twitter:description, twitter:image) for the X ecosystem
• Use 1200x630px images in JPG/PNG, accessible via HTTPS, with absolute URLs
• Test each URL with Facebook Sharing Debugger and Twitter Card Validator before the campaign
• Force re-scraping after any tag modification via debug tools
• Eliminate duplicate tags caused by poorly configured plugins or themes