Consumer Reports: Getting the cheapest holiday airfare

PHILADELPHIA (WPVI) -- Holiday travel is right around the corner so we've got tips on how to find the cheapest price.

If you're planning a flight for the December holidays and haven't booked yet, do it soon. Consumer Reports says if you wait much longer, you'll likely see prices jump.

For many air travelers, a bargain is what matters the most.

"I mean, I definitely try to get the best deal that I can get," said one traveler.

But which booking site will give you the best deal?

Consumer Reports compared nine sites, searching for the cheapest nonstop roundtrip flights on five busy domestic routes.

Users simultaneously searched for the exact same itinerary at the same time to the same airport.

They found there can be big differences. For example, in one search for New York to Miami round-trip flights, the cheapest fare Google Flights came up with was $597 dollars, but on Priceline the cheapest was $459 dollars.

And despite its name, CheapOAir never came up with the lowest fare on any of the routes that Consumer Reports checked.

"We found you'll increase your odds of finding the lowest fare if you search for flights multiple times over multiple days with and without your search history cleared on your browser," said Mandy Walker, Consumer Reports Money Editor.

Also, check the airlines own sites to see if you can find an even lower fare. You can find all airlines that serve a given route at Google.com/flights.

Fares can vary considerably for flights just hours apart and at nearby airports. Consumer Reports found Kayak makes it particularly easy to search for other options.

With prices changing all the time, Consumer Reports says it's a good idea to check the day after you book to see if you can find a better deal. By law you can cancel without penalty for 24 hours after you book it, as long as you're not traveling for at least a week.

And when it comes to Thanksgiving travel, Consumer Reports says avoid traveling on the Wednesday before Thanksgiving or the Sunday after.

The fares are higher on those days and the airports will be at peak congestion.