DesignRush SEO Roundup: Google Core Update, AI Overviews Drop, Indexing Fix

Each week, the DesignRush SEO team breaks down the latest updates shaping search and paid media. Teams looking for expert support can explore our full directory of vetted SEO agencies.

This week brought the most significant ranking disruption in months, surprising data on AI search visibility, and critical technical fixes.

Here's the breakdown of the biggest and most recent SEO developments.

Search Ranking Volatility

Google's December 2025 core update is showing early, intense impact on traffic across the industry.

SEOs worldwide are reporting significant traffic and ranking drops, with some sites experiencing double-digit percentage declines in organic visibility.

Experts suggest the updates point to a workaround for blocking bots and automated traffic, with Google surfacing more pages in search results while ranking them lower.

Indexing and Technical Fixes

Google resolved a month-long delay with its page indexing report, which now reflects data as recent as a few days ago.

It also advised sites to keep canonicals consistent before and after rendering, noting that mismatches between raw HTML and JavaScript output can lead to unexpected indexing behavior.

Google Search has also added “read more” links to search result snippets, directing users to specific sections of a page.

AI Overview Decline

An Ahrefs study found that only 13.7% of citations overlap between AI Overviews and AI Mode, showing the two features rely on largely different source sets.

Google is also testing long, expandable AI-generated snippets in search results, a change that could further reduce click-through rates to websites.

AI Overviews now appear in fewer than 16% of queries as of November, down sharply from more than 25% in July.

SEO Community Response

Chris Long, co-founder at Nectiv, noted that location-based pages often play a central role in AI search visibility, reinforcing the value of geographic targeting.

Surfer SEO published a case study showing how a structured content overhaul helped an SEO newcomer reach more than 230,000 clicks within seven months.

This underscores the continued impact of core SEO fundamentals even amid ranking volatility.

SEO consultant Matt Diggity cautioned that API-based tools tracking AI visibility can diverge sharply from what users actually see, citing tests comparing API data with scraped results from ChatGPT and Perplexity.

Caleb Bradley, founder and CEO of eCommerce development firm Bighorn Web Solutions, says this gap has direct consequences for online retailers.

“eCommerce teams lean heavily on third-party tools and are among the most exposed when visibility data is off," he explained to DesignRush.

"If AI tools say a product or category page is performing when users aren’t seeing it, merchandising, inventory, and content choices start drifting off course.

That’s why real-world checks matter more than dashboards when revenue is on the line.”

These observations point to several pressures hitting search teams at once.

The December core update is driving the most pronounced ranking volatility of the year.

AI visibility is fragmenting as Google reduces AI Overview's presence and separates features.

At the same time, technical basics like canonicals and rendering accuracy are proving increasingly decisive as indexing rules tighten.

How search teams should respond:

• Track the December core update impact closely to identify which content types gain or lose visibility.
• Strengthen technical consistency, especially canonical alignment across raw HTML and rendered pages.
• Separate AI visibility measurement from traditional rankings, validating exposure through real user searches, not APIs alone.

The fundamentals haven't changed, but the execution bar is rising as Google refines what qualifies as high-quality content.

Our Take: Is Google Recalibrating Its AI Strategy?

The sharp AI Overviews decline indicates that Google is rethinking how aggressively to deploy generative features.

The December core update feels more severe than previous 2025 rollouts, indicating fundamental changes to content quality evaluation.

I suspect this is part of a larger recalibration as Google balances AI-driven answers with maintaining a healthy ecosystem of content creators.

However, generic content won't cut it anymore when AI can answer questions directly in the SERP.

Brands would need original research, expert analysis, or proprietary insights that can't be generated by AI.

For more on Google's transparency shift and Search Console AI features, check out last week's SEO roundup.

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