What it is based on
The algorithm takes into account dozens of factors – traffic, user behavior signals, the website’s technical condition, the presence of original content, and the brand’s online reputation. The exact formula is not disclosed. Historically, the SQI scale was tiered and inherited values from TIC (10, 20, 40, 80, 150, and so on), but after the 2019 update, Yandex made the calculation more precise and dynamic, so intermediate values are also common today.
What it means in practice
SQI is useful for comparison with direct competitors in a niche and for tracking a website’s overall dynamics over time, rather than as a metric that directly moves rankings. A sharp increase is usually associated with growth in actual traffic, user behavior signals, or significant technical changes, but it does not guarantee growth in search results.
Who it matters to
It is especially important for websites without access to in-depth position analytics for each query: small websites, websites built with site builders, and new projects. For large platforms with a broad range of queries, SQI is less indicative – they focus directly on traffic and conversions.