Everyone asks: which site will get me the best airfare?

WHICH IS THE BEST FLIGHT SEARCH ENGINE FOR TRACKING DOWN A CHEAP AIRFARE?

If only life was so simple. There is no "best" search engine that will deliver the sharpest deal every time.

Flight search engines fall into two categories, those of the consolidators and those of the aggregators.

Consolidators operate by buying blocks of seats directly from the airlines at low rates, adding a commission and reselling them either to travel agents or over their websites. These tickets generally come with more restrictions than if you buy from the airline itself. For example you may not be eligible for frequent flier points or advance seat selection, and changing an itinerary might be impossible. Airfare.com and CheapTickets are just a couple of examples of consolidators.

Aggregators give you a more comprehensive view. They scour airline websites as well as consolidators' websites and online booking agencies such as Expedia and Travelocity to find the keenest deal. They make their money from the commission paid for a booking made through their website.

Some of the best performing aggregators are Kayak, Momondo, Mobissimo and Hipmunk, but they won't necessarily charge you the same fare, even when their search engine responds to your query with the same route, on the same day aboard the same airline.

Only by searching multiple aggregator sites will you find the absolute rock bottom airfare.