In 2019, the SEO landscape underwent several foundational shifts shaping the search ecosystem for years. The year was defined by the rise of contextual understanding through machine learning, a stronger push toward trust signals, and increased scrutiny of search result diversity. For SEO professionals, the focus moved beyond traditional keyword matching and toward intent modeling, user trust, and technical structure.
Major Google Algorithm Updates
March 2019 Core Update
Initially referred to as the “Florida 2” update, the March core update heavily affected health and YMYL sites. It rewarded websites that had taken steps to improve trustworthiness, factual accuracy, and overall page quality. Google emphasized that the update was not targeted at specific tactics but rather part of an ongoing refinement of content evaluation.
June 2019 Core Update
This was the first time Google pre-announced a core update. The update continued reinforcing E-A-T principles, especially for finance, news, and health domains. Google also began deprioritizing sites using clickbait headlines or overly aggressive monetization strategies.
September 2019 Core Update
This update focused more on relevance and alignment with searcher intent. Several SEOs noted that it helped rebalance volatility from earlier updates. While the update was broad in scope, sites with a well-maintained content structure and clear topical depth tended to benefit.
BERT Update – October 2019
The most impactful development of the year, BERT (Bidirectional Encoder Representations from Transformers), was officially integrated into search for English-language queries. BERT allowed Google to understand better natural language, especially prepositions and the context of complex queries.
Although BERT was not something SEOs could directly optimize for, it forced a strategic shift:
- Emphasis on writing content that addresses specific questions and nuanced intent
- Reduction in the effectiveness of over-optimized, keyword-stuffed content
- Rise in importance of content clarity and semantic structure
Site Diversity Update – June 2019
In response to feedback that too many results on the same query were dominated by a single domain, Google launched the Site Diversity Update. This aimed to limit the number of times a single domain could appear in the top search results for a given query. It did not apply to branded or highly authoritative searches but signaled Google’s commitment to more balanced SERPs.
This development challenged SEOs to focus on broader keyword targeting, long-tail content strategies, and subdomain diversification when appropriate.
E-A-T and Content Credibility
While not a new concept, E-A-T (Expertise, Authoritativeness, and Trustworthiness) became more central to SEO success in 2019. This was especially true for YMYL (Your Money or Your Life) content, where Google increased reliance on external trust signals and factual accuracy.
Key trends included:
- Growth of author bios and visible credentials
- Increased scrutiny of backlink quality and relevance
- Rise of reputation management as part of SEO strategy
SEOs were encouraged to invest in thought leadership, digital PR, and content authenticity rather than purely technical tactics.
Featured Snippets and Structured Data
Featured snippets continued to gain visibility and importance in 2019. Google also expanded the use of structured data, with new schema types including:
- FAQPage
- HowTo
- Product enhancements
- Review snippets
The adoption of structured data became a competitive differentiator. SEOs who implemented schema markup saw improved SERP visibility through enhanced listings and increased snippet eligibility.
Mobile-First Indexing Progress
Although introduced in 2018, mobile-first indexing became the default for all new websites in July 2019. Google continued to shift its crawling and indexing priorities to mobile content.
This impacted SEO strategy in the following ways:
- Mobile performance and UX had to be equal to or better than desktop
- Responsive design and structured mobile menus became essential
- Mismatched content between desktop and mobile could result in indexation issues
Strategic Takeaways for SEOs
- Natural language and context became key
With BERT, Google began evaluating how content addressed specific searcher needs, not just how it matched keywords. - Content credibility directly influences rankings
Author bios, trust signals, and clear sourcing became essential for industries where accuracy matters. - SERP competition intensified
The diversity update and growth of featured snippets made it harder to own multiple listings. SEOs had to diversify tactics and optimize for rich results. - Structured data gave early adopters a clear edge
Schema markup improved visibility, especially for e-commerce, how-to content, and FAQs.
Conclusion
2019 marked the beginning of Google’s transformation into a more contextual and user-centric search engine. The introduction of BERT and increased focus on E-A-T required SEOs to prioritize clarity, authenticity, and relevance. Although many tactics from prior years remained useful, they were no longer sufficient in isolation.
For SEO professionals, long-term success in 2019 meant adapting to machine learning advances, building content that served human intent, and enhancing credibility across every touchpoint.