Definition
RankBrain is an artificial intelligence component of Google's algorithm announced in October 2015. Based on machine learning, this technology allows Google to interpret never-before-seen search queries (approximately 15% of daily searches) by connecting them to known concepts. RankBrain analyzes user behavior patterns, notably click-through rates and time spent on pages, to continuously refine result relevance. Google has confirmed that RankBrain is one of the three most important ranking signals, alongside content and links.
Key Points
- First AI component integrated into Google's algorithm
- Interprets previously unseen queries through machine learning
- Third most important ranking factor according to Google
Practical Examples
Ambiguous query interpreted
For a query like 'apple cheap', RankBrain determines from context and trends whether the user is looking for an iPhone or fruit, and adapts results accordingly.
Synonyms and related concepts
RankBrain understands that 'how to lose weight' and 'methods for slimming down' express the same intent and displays similar results for both queries.
Frequently Asked Questions
There is no direct optimization for RankBrain. The best approach is to create comprehensive content that clearly answers search intent, improve user experience, and aim for a high click-through rate in results through compelling titles and meta descriptions.
No, RankBrain works alongside other factors. It helps Google better understand queries so it can then apply traditional ranking signals like content relevance and link authority.
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Last updated: 2026-02-07