In Semrush, SF means SERP Features. It appears in keyword reports to show how many special result types are present on Google’s results page for that keyword, beyond the standard organic listings. These features can include things like Featured Snippets, People Also Ask boxes, local map results, image packs, video results, sitelinks, and shopping results.
When you see an SF value, it’s a quick signal that the search results page is more “crowded” and that rankings alone may not tell the full story. A keyword with lots of SERP features can reduce organic click potential if Google is answering the query directly, but it can also create opportunities if you can earn placement inside a feature. Use SF to judge competitiveness, understand intent, and decide whether you should target a traditional ranking, aim to capture a feature, or choose a different keyword with a cleaner results page.