On a recent search of Kayak, for a flight from New York to Los Angeles in February, I was quoted rates starting at $299 round trip on Continental. When I refined my search for nonstop flights departing before 11 a.m., the cheapest rate increased to $389. To find the true cost of the trip, I clicked on "add baggage fees" and input the number of bags I might check (one). Kayak automatically recalculated the fares. Checking one bag each way would bring the total to $425. Clicking on "details" showed the number of seats left on the flight: nine.
Having researched the fare on Kayak, I visited Bing Travel next. It offered the same search results minus the baggage calculator. But it had its own nifty feature, the Price Predictor, which uses algorithms to determine whether a fare is likely to rise or fall during the next seven days, which can help when trying to decide whether to buy now or wait for a better rate. Predictions are offered between 75 top domestic markets and from the United States to some major European destinations. For the New York to Los Angeles flight, the site showed a red arrow pointing down and recommended waiting ("fares dropping $50 +). Clicking on "details" for the prediction offered this caution: "Price drops are sporadic and 50 percent of them do not last longer than 48 hours. Consider your risk tolerance."
But it was Fly.com that found the best bargain for a morning nonstop: $362 on American, departing from Kennedy and returning to Newark. Clicking "summary" offered a side-by-side snapshot of economy and business or first-class seats in case I wanted an upgrade. But with rates for first class more than $1,000 extra, I preferred to stay in coach.
Fly.com says it searches Travelocity, Hotwire and Priceline on one screen so you don't have to open a series of windows on your computer and toggle back and forth as you do with Kayak or Bing Travel for those sites. (Kayak and Bing allow users to search those sites in a separate window by clicking a box at the start of their search or on the flight results page.) Fly.com also pulls fares from international consolidators, such as Vayama.com and Airfare.com, which negotiate contracts with the airlines to sell tickets below the lowest published price. A recent search for flights in early March from Los Angeles to Sydney, for example, offered a round-trip nonstop through Vayama.com on Qantas for $1,087. The cheapest nonstop offered by Kayak was $1,139 on Delta. (Kayak allows users to search Vayama and Airfare.com in separate windows by clicking a box at the start of the search.)
By aggregating fares from these other sources, Brian Clark, general manager of Fly.com, says, the site often finds a lower fare, especially on international routes. In its own comparison with Kayak, Fly.com said it found a lower fare 16 times and matched Kayak's price six times in a search for international flights across 25 routes.
Not to be outdone, Kayak asked a third party to run 237 searches, selected randomly. Twenty-three percent of the time, Kayak was cheaper. "Nobody will beat us (on average) on fares in the US and Europe," English of Kayak wrote in an e-mail message. Kayak, he said, pulls fares from Amadeus, a global distribution system, in addition to ITA Software, and searches some major airlines directly. But he also pointed out that "no one company can always have the cheapest flight or hotel for every single search." Indeed, Fly.com doesn't always offer the cheapest fare. In my own search for flights in early March from Detroit to Orlando, Fla., Kayak and Bing beat out Fly.com by $36.
