How do you find the best airfare? Click. Click again. Click again. Then click some more.

According to figures compiled by the Web analytics firm, travelers made an average of 21 visits to various travel websites last year before finally booking a trip.

That's a lot of time surfing the Web -- and a possible business opportunity for travel sites that can make that search faster and easier. Now, several "meta-search" firms are offering to do just that, each promising that their users will either find the cheapest fares or spend less time searching for them.

These meta-search sites -- among them,, and -- don't sell plane tickets or control bookings at hotel rooms. Rather, they search hundreds of travel sites at once in a quest to identify the best rates and then send consumers to book directly at the seller's site.

All have recently been raising their profiles -- Kayak with a new TV ad campaign that trumpets its supposed primacy ("Search One and Done"); Momondo, a Danish company, with a site that boasts it is "the best flight search engine" on the Web; and Fly, with one-on-one sessions with reporters from national publications asserting that its fares either match or better Kayak's in "46 of 50 top markets." (The latter claim draws this response from one of Kayak's founders, Paul English: "Ridiculous.")

Kayak, Fly and another meta-search site, Bing Travel from Microsoft, all work with ITA Software for certain search capabilities and access to fares. ITA pulls fares from the Airline Tariff Publishing Co., which collects prices from 500 airlines worldwide. That means many of the meta-search sites are dipping into the same pool of data.

But there are decided differences.

Each site has unique features

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 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. 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.) also pulls fares from international consolidators, such as and, 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 on Qantas for $1,087. The cheapest nonstop offered by Kayak was $1,139 on Delta. (Kayak allows users to search Vayama and 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, says, the site often finds a lower fare, especially on international routes. In its own comparison with Kayak, 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, 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 by $36.

Each meta-search site configures its technology and accesses fares slightly differently, which can affect results. Where the sites also tend to differentiate themselves is through special partnerships and features that might cater to a certain segment of travelers. "No one site can necessarily do it all for everybody right now," said Henry Harteveldt, a travel analyst at Forrester Research.

Planes and trains in Europe, the Danish travel search site, for example, uses intelligent Web crawlers to scour the airlines' own websites as well as online agencies, focusing on low-cost carriers, some of which are often missed by U.S. meta-search sites. (LyddAir anyone? How about Snowjet?) Because of the way Momondo pulls fares, however, it must often use cached data, which can result in expired fares showing up.

But Momondo says it is working on the issue, and it is still worth a look if you're searching for the cheapest way to get around Europe. The site recently began comparing rates with more than 4,000 high-speed train routes across Europe. Searching for flights in early March between Paris and Amsterdam turned up nonstop round-trip prices from $311 on But Momondo also offered high-speed train trips from $178 on Thalys, adding about an hour of travel time to the trip. One caveat: Travelers must re-create their train search when redirected to the booking site.

In the end, I was comfortable that I had found the best deal, during the window that I had searched. Looking back, I visited just a handful of sites, much fewer than the average of 21 visits, but still far more than the promise of a one-stop shop.