Safe Browsing
Also known as: smartscreen, url reputation
A browser service that warns before you visit a known phishing or malware site.
Google Safe Browsing, Microsoft SmartScreen and Apple's equivalent maintain constantly-updated lists of dangerous URLs. Browsers check requested pages against those lists — usually via a hashed, privacy-preserving lookup — and show a full-page warning on a match.
Safe Browsing catches broad, well-known threats fast. It doesn't replace layered defences: ad blockers stop malvertising the reputation feed hasn't seen yet, password managers refuse to autofill on look-alike domains.