Linkcheck

How it works: two halves. The first reads the link itself and never touches the network — it catches the tricks that fool people most, like a Cyrillic character standing in for a Latin one so that a fake domain renders pixel for pixel like the real thing, or a name such as paypal.com.secure-login.ru where the part that actually decides the destination is buried at the end. That runs instantly and offline. The second half is optional and does leave your browser: it asks Roam's server to follow the link and report back where it lands, what certificate is there and how old the domain is. A domain registered nine days ago that claims to be your bank is the single loudest signal there is. Nothing about the destination can be known without asking, so that half is yours to choose.