Core update
A significant, broad change to Google's ranking systems, announced in advance and rolled out over one to several weeks, typically a few…
AlgorithmsRanking systems guide
Google ranking systems
Google's documented list of the systems that generate rankings, distinguished from one-off 'updates' to those systems, and including retired ones.
In full
The guide names current systems such as BERT, deduplication, exact-match domain handling, freshness, helpful content signals, link analysis, local news, MUM, neural matching, original content, page experience, passage ranking, product reviews, RankBrain, reliable information, reviews, site diversity and spam detection. It also lists retired systems — including Hummingbird, mobile-friendly ranking, page speed and Panda — whose functions were absorbed into core ranking. Reading it prevents chasing algorithms that no longer exist as separate entities.
Example
A team checks the guide and finds the Helpful Content system is no longer listed separately because it was integrated into core ranking in 2024.
Related terms
BERT
A transformer language model Google applied to search from 2019, improving understanding of word order, prepositions and context within…
RankBrain
Google's first machine-learning ranking system, introduced in 2015, which helps interpret how queries relate to concepts, especially…
Helpful content system and updates
A Google system launched in August 2022 to demote sites with a high proportion of content made for search engines, integrated into core…
Deduplication system
Google's system for ensuring results are not dominated by near-identical pages, filtering duplicates so users see a varied set of sources.