Sparkfare checks flight prices against each route's own price history and shows the comparison with its basis. A price is only called a deal when it is well below that route's own recent median and there is enough history to judge it. Routes without enough history are marked "Building history" rather than given a verdict.
Fares come from cached search data supplied through Travelpayouts (Aviasales). Every price shows when Sparkfare retrieved the data; the fare itself can be older and may no longer be available when you click. It is not a live quote and it is not a prediction. Today Sparkfare tracks 880 routes: 22 US hubs and 40 destinations.
Sparkfare publishes fare information and price-history analysis, and sends you to Aviasales, which handles booking and payment. Sparkfare doesn't sell, book, ticket, arrange or take payment for travel, and it isn't owned by an airline or a booking site.
Sparkfare may earn a commission if you buy through a link, at no extra cost to you. That covers fare links to Aviasales and the partner links in Away Mode. Commissions do not change which fares are shown or how they are ranked: ranking uses only each route's own price history. See the affiliate disclosure for the current partners, and how we rank deals and why commissions don't influence ranking for the method.
Away Mode is a short checklist for the things to sort before a trip: mail, water, pets and a few services. Some of the services link to partners; the home and pet items are plain instructions with no link.
Questions, corrections or data requests: hello@sparkfare.com. The privacy policy says what Sparkfare stores and why.