As we reach the final days of 2025, Google delivered one more significant update to keep us on our toes. The December 2025 core update, the third of the year, is currently rolling out as I write this on 29th December, and it’s already causing substantial ranking shifts across numerous industries.
Let’s look back at what’s happened in December and what it means as we close out this transformative year in search.
The Google December 2025 Core Update
On 11th December, Google announced the December 2025 core update, stating it would take up to three weeks to complete. That means, as I’m writing this, we’re about two and a half weeks into the rollout, with completion expected in early January 2026. Actually, scratch that – as I’m writing I can see that the rollout has completed!
This is the third core update of 2025, following the March update (13th-27th March) and the June update (30th June-17th July). Combined with the August spam update, it means we’ve now had four major confirmed algorithm updates this year – exactly what Google had hinted at when they promised “more frequent updates” at the start of 2025.
According to Google’s announcement, this is:
“…a regular update designed to better surface relevant, satisfying content for searchers from all types of sites.”
In other words, it’s not targeting specific issues like the spam update did, it’s recalibrating how Google evaluates overall content quality across the board.
Earlier reports from the SEO community suggested this update hit hard. Barry Schwartz noted that SEO forums were already buzzing with reports of significant movement before the official announcement, and early insights indicated large ranking swings, with some site owners reporting significant movement.
What the December 2025 core update means for you: If you’ve seen ranking volatility, keep calm and avoid making any unnecessary changes to your website. Google core updates typically show ups and downs throughout the rollout period, with rankings sometimes swinging multiple times before settling again. Because this rollout has only just completed within the last few hours, we should see where our websites sit in the grand scheme of things.
Google Confirms Unannounced Updates Are Regular
Talking of core updates, the other significant piece of news on the 8th December was Google’s updated documentation about how updates work. Two days before announcing the December core update, Google added new guidance to its core updates documentation explicitly stating that it regularly rolls out smaller core updates that aren’t announced because they’re not widely noticeable.
This officially confirms what many of us in the SEO community have suspected throughout 2025: those mysterious periods of volatility without announcements weren’t our imagination, they were real, unannounced algorithm adjustments.
Google’s documentation now makes clear that sites don’t have to wait for major core updates to see improvements. If you’ve invested in stronger content, better site experience, or higher expertise signals, smaller algorithm adjustments may lift your visibility at any time.
What regular unannounced updates mean for you: This changes the game somewhat. Rather than the old model of “wait for the next core update to potentially recover”, continuous improvement can yield results at any time. However, Google notes that major core updates still tend to have more substantial impact. The key takeaway here is that you shouldn’t just make changes after updates but rather you should continuously improve your content quality and site experience.
This ties in exactly with what I’ve been seeing and saying since around 2014 when I left the is4profit small business website – its new owners didn’t seem to attend to the site as much as I did (daily for at least 6 or 7 years) and so its traffic eventually “dropped off a cliff”. I’ve always maintained that if you run a business website then look after it – every day if you can.
Search Console Reporting Delays
Throughout most of December 2025, Google Search Console (GSC) experienced significant reporting delays.
Google has assured users that visibility in search isn’t actually impacted and data should catch up once they resolve the reporting backlog. However, this has made it challenging for SEOs to accurately track the impact of the December core update in real-time.
What GSC reporting delays mean for you: If your Search Console data looks frozen or unusual, this is why. Your actual search visibility hasn’t changed; it’s just the reporting that’s delayed. Use third-party rank tracking tools (SEMrush, Ahrefs, Moz) for monitoring during this period, and wait for GSC to catch up before drawing conclusions from that data.
AI Mode is Coming to Google Discover
Google announced that AI Mode features are coming to Google Discover, expanding the AI-powered search experience beyond traditional search queries. This integration will bring the conversational, in-depth AI responses to the personalised content feed that millions of users see on their mobile devices, me included.
Additionally, Google is increasing the number of inline links in AI Mode and updating the design of those links to make them more useful, improving transparency in Google’s generative summaries.
What AI Mode in Google Discover means for you: If you’ve already been optimising for Google Discover by creating fresh, engaging content with high-quality images, then you now need to think about how that content might appear in AI Mode responses as well. The principles remain the same – quality, expertise, engaging presentation. But now it’s the interface that’s continuing to evolve.
Google News Gets “Preferred Sources” Globally
Google rolled out “Preferred Sources” globally for English language users, a feature that allows searchers to customize their Top Stories feed to prioritise specific publishers. Google reports that users are twice as likely to click through to a site if they have marked it as a “preferred source”.
Google is also bridging the gap between paywalls and AI by introducing a feature that highlights and prioritises links from a user’s active news subscriptions directly within the Gemini app, with plans to expand to AI Overviews and AI Mode.
Additionally, Google unveiled a commercial partnership pilot with major global outlets, including The Guardian, The Washington Post, and Der Spiegel, to test AI-driven engagement tools.
What Preferred Sources mean for you: For news publishers and anyone creating timely content, encouraging readers to mark you as a “preferred source” becomes a valuable engagement strategy. If users are twice as likely to click, getting on that preferred list is worth promoting. For subscription-based publishers, the integration with Gemini and future AI features could help drive value from paywalled content.
New Search Console Social Media Tools
Google introduced new Search Console tools that provide insights into your brand’s social media profiles. This integration allows you to see how your social media presence connects with your search visibility.
What this means for you: If you maintain active social media profiles, connecting them through Search Console can provide valuable data about how they contribute to your overall online presence. This reinforces the trend we’ve seen all year: search visibility increasingly depends on building a comprehensive online presence, not just optimising your website.
ChatGPT Shopping Features Continue Expanding
Throughout December, ChatGPT continued expanding its shopping features, allowing users to search for and discover products directly within the chat interface. This builds on the rollout that started in late April and underscores how AI platforms are becoming genuine search alternatives for commercial queries.
What this means for you: If you run an e-commerce business and haven’t already ensured ChatGPT can access your product data, this should be a priority for 2026. Whilst traditional search remains dominant, having visibility across multiple AI platforms provides valuable diversification.
The LLMs.txt Mystery
Now here’s an interesting development: some eagle-eyed SEOs spotted a live LLMs.txt file on Google’s Search Central subdomain. However, it quickly disappeared and the page resolved to a 404.
For context, llms.txt is a proposed standard for helping AI systems understand how to access and use website content. Google has previously taken a negative view of it, calling it largely redundant. The brief appearance on a Google subdomain got many excited, but it appears to have been an accident rather than an intentional policy change.
What LLMs.txt means for you: For now, llms.txt remains an interesting idea without widespread adoption. You should continue to focus on structured data (schema.org) and proper robots.txt management rather than implementing llms.txt unless major platforms officially support it.
Early Patterns from the December Update
Whilst the update is still rolling out, some early patterns are emerging from tracking data and community reports:
Sites seeing positive impacts:
- Sites with clear expertise and experience signals,
- Content demonstrating original research or unique insights,
- Well-maintained sites with recent updates and fresh content,
- Sites with strong E-E-A-T signals (credentials, author bios, citations).
Sites seeing negative impacts:
- Generic content that could be written by anyone,
- Sites with thin, templated pages,
- Content that lacks specific details or practical examples,
- Sites with outdated or poorly maintained content.
Interestingly, domains from health, finance, reference, travel and adult topics can be seen in both winners and losers, suggesting it’s not about industry but about quality within each industry.
The Big Picture: 2025 Ends as It Began
December’s developments nicely bookend a year that’s been characterised by continuous change. We started 2025 with Google promising more frequent updates, and we’re ending with the third core update of the year plus confirmation that unannounced updates happen regularly.
The key themes from December:
- Quality is enforced more strictly than ever. Each core update has raised the bar for what Google considers helpful, satisfying content.
- Continuous improvement matters. You don’t need to wait for major updates—ongoing enhancements can show results at any time.
- AI features keep expanding. From AI Mode in Discover to shopping in ChatGPT, AI-powered search continues growing.
- Multiple platforms matter. Search visibility now spans traditional search, AI platforms, social media, and news feeds.
- Expertise and experience are non-negotiable. Demonstrating real knowledge and first-hand experience consistently helps across all updates.
What You Should Do Right Now
Now the December core update has finished rolling out:
During the rollout (now through early January):
- Monitor your rankings but don’t make major changes yet,
- Document what’s changing and when relative to the rollout,
- Review your analytics for traffic and conversion impacts,
- Prepare a list of improvements to implement once things settle.
Once the update completes (early January):
- Assess the overall impact across your site,
- Compare your content to what’s now ranking above you (if you dropped),
- Identify patterns in what gained or lost rankings,
- Develop a strategic improvement plan based on clear quality signals.
For 2026 planning:
- Accept that volatility is the new normal and build resilience,
- Focus on continuous improvement, not just reactive changes,
- Diversify your traffic sources beyond just organic search,
- Invest in demonstrating genuine expertise and experience (E-E-A-T),
- Keep your content fresh and regularly updated.
Looking Forward to 2026
As we close out 2025, the December core update reminds us that search evolution never stops. We’re heading into 2026 with:
- AI features ever more deeply integrated into search,
- More frequent algorithm adjustments (both announced and unannounced),
- Even higher standards for content quality and expertise,
- A more complex, multi-platform search ecosystem.
The sites that will thrive in 2026 are those that embrace quality as an ongoing commitment rather than a one-time optimisation task.
Need a Fresh Start for 2026?
If the December update has negatively impacted your site, or if you simply want to start 2026 with a comprehensive SEO strategy that’s built for the modern search landscape, I’m here to help.
For local businesses in Farnborough, Hampshire, and the surrounding areas, I offer SEO audits, strategic consulting, and ongoing management that focuses on sustainable quality rather than quick fixes.
Let’s use the December update as an opportunity to assess where you are and develop a plan for where you want to be in 2026. Drop me a message through my contact form.
Here’s to finishing 2025 strong and making 2026 your best year yet for search visibility.
Paul Mackenzie Ross is an SEO consultant based in Farnborough, Hampshire, specialising in helping local businesses improve their online visibility and attract more customers through search engines and AI platforms.
Call him on 01252 692 765 for help with hosting, website design, content, and all things digital marketing, especially SEO.
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