Kayak

Kayak is a flight metasearch that never sells you the ticket — it aggregates fares from hundreds of airlines and OTAs, then redirects you elsewhere to actually buy. The homepage states the model outright: "Find the right flight from 100s of sites," over one form spanning Flights, Stays, Cars, Packages, and Cruises. Results sort by Best, Cheapest, or Quickest above a deep filter rail — stops, airlines, times, bag fees — and a right rail that literally compares Kayak against rival sites. Pick a flight and the booking panel reveals the catch: the fare's fine print (no carry-on, paid checked bag, no refunds) and a "Book on Kiwi.com" handoff to a third party. The aggregation is genuinely useful, but the page is dense with house ads and sponsored "official site" results that blur into the organic list.