AGS is an acronym for a filter on the Yandex search engine, introduced to combat low-quality, poorly optimized and content-poor websites. Its name comes from the Russian language (Anti-Govno-Site) and directly describes its goal: to remove “garbage” sites from search results that do not provide any value to the user.
Conceptually, AGS is analogous to early Google quality filters (such as Panda) and focuses on identifying sites created solely for the purpose of profiting from advertising or links, without investing in unique, useful and well-structured content. The penalty imposed by AGS is usually very severe, and can lead to the complete exclusion of the site from the Yandex index.
AGS is an example of an algorithmic fight against the artificial commercialization of search. It affirms the principle that long-term success in SEO requires a commitment to user-friendly quality and originality, rather than attempts to manipulate the algorithm through cheap or automated content.