The fight: Flight aggregators
Tools that pull from hundreds of booking sites simplify flight search. Which aggregator will get you to the beach first?
Kayak: Offers fare alerts and historical price charts. Shows fares that combine different carriers. More international options.
Google Flight Search: Lightning-fast search results. Flight Explorer feature lets you enter a date range and see the lowest fares for multiple destinations.
Kayak: Comparatively slow search results.
Google Flight Search: No mobile app or ability to set fare alerts. Only fares that include one domestic leg.
Kayak: The original triumphs. Remember, though, airline sites may have offers that don't show up on either, says George Hobica of Airfarewatchdog.com.
Availability: Both sites are available on their individual websites. Kayak is also available on the iPhone, Android and Windows Phone. Both apps are free.
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