Have you ever wondered if there is any difference in the prices you are quoted from different airfare websites when you go searching for a flight? I think most of us assume they all tend to show the same fares, but is that assumption true? We at BootsnAll decided to put it to the test.

What we decided to do was test seven major airfare search sites against each other to see how they stacked up in a side-by-side challenge. We compared five of the traditional travel booking sites along with two of the new breed of airfare "aggregators". These new aggregator sites search every applicable site themselves, including the airlines' own sites, and then send you to the one offering the lowest price. Would they all end up with the same deal? Let’s find out.

How the test was conducted

We wanted to be as scientific as possible so here’s how we compared them: Before running any price tests, we invented six various trips that we would test on each different airfare website. There wasn’t much reason to think one site would do well with only one type of trip, but we still wanted to mix up a variety of scenarios in order to make the results more meaningful. We chose both popular routes and rare combinations of cities. We chose very specific flight criteria as well as open schedules. We also included a variety of domestic US and international destinations, as well as a mix of nonstop, multi-stop and one-way fares. And since we know that fares and availability can change throughout the day, we concentrated on one trip at a time, to get results from each of the seven sites in as little time as possible. Each trip was priced on all sites within a 10-minute period.

The six test itineraries

Trip 1: Los Angeles to San Francisco, nonstop, leaving next Friday between noon and 8:00 p.m., returning Sunday between 9:00 a.m. and 6:00 p.m.

Trip 2: Portland to Baltimore, one stop, leaving anytime three weeks from Saturday, returning anytime the following Saturday.

Trip 3: Las Vegas to Toronto, nonstop or one stop in eight hours or less, leaving anytime on a specific Thursday next month, returning anytime the following Sunday.

Trip 4: Austin to London, one stop, leaving anytime on a Friday or Saturday next month, returning 10 days later on a Monday or Tuesday.

Trip 5: JFK to Miami, nonstop, one-way, leaving anytime on a specific Monday or Tuesday four weeks from now.

Trip 6: Omaha to Singapore, no more than two stops, leaving on a specific Saturday in two months, returning one week later.

The results

The conclusion

On the least complicated trips, all the sites found the exact same flights, which allows us to clearly see that several of them charge around $5.00 per ticket more than the rest. Specifically, Hotwire and Priceline offered the lowest prices on the simple round-trips; Kayak and Sidestep sent users to the individual airline site that offers those same prices (where users can complete their purchase with only a few more clicks). Expedia, Orbitz and Travelocity offered nearly identical prices, which were slightly higher than the others.

On the more complicated trips (to London and Singapore from smaller US cities), the results were spread out a bit more. Based strictly on our predetermined criteria, they didn’t all find the same flights. And in both of these cases, Priceline came out lowest of all. Their London trip was almost $10.00 lower than the next cheapest; their Singapore trip was over $90.00 lower than any of the others.

Final score, from worst to first

Hotwire (average, $552.30) – In our tests they tied for cheapest on two of our trips, but on three others, they missed cheaper flights that most of the others found. Also, since they don’t currently book one-way tickets, they send the user to Expedia, so that higher price was used.

Expedia ($542.27), Orbitz ($507.00) and Travelocity ($507.68) – These sites clearly charge an extra $5.00 or so per ticket on many flights, though their searching ability did perform well. Expedia failed to find the cheaper trip to Singapore, but on the other five sample trips, they all performed almost identically.

Kayak ($503.85) and SideStep ($503.85) – The two aggregators (which search every applicable travel site for you and then send you to the cheapest site to finalize the purchase), performed identically in every way. On the London trip they both showed the same lowest price as Priceline, but upon reaching the airline site to finalize the purchase, it wasn’t available, even after several tries starting from the beginning. They both do an excellent job of finding the best fare, but their inability to actually let you book that fare themselves can lead to frustration and the occasional missed opportunity.

The WINNER based on price alone

Priceline ($486.33) – This was a bit of a surprise, but Priceline essentially tied for cheapest on four trips, and found the absolute cheapest price on the other two. Their recent slogan change to “no booking fees” seems to be more than a gimmick. They always found the lowest price with no dead-ends, like on Kayak and SideStep.

However…

These tests were done based on price alone, and there were a lot of ties among the sites. If you’ve tried more than a couple of these airfare engines, you know that the searching and booking procedure on each one can vary greatly. Next we’ll test each site for ease of use while searching for the lowest fares.

Check out our cheap air ticket resource to find out which airfare site will work for you.

Next up: Which is the best airfare site if you know exactly what you want?