The Best Airfare Search Engines for Finding Cheap Flights
ListMyStartup’s regularly pits the best airfare search engines, aggregators, and booking sites against each other in a battle royale to see which can find the lowest price on more than two dozen identical searches.
This year’s race saw quite a shakeup. Some of the most famous names (FareArena, Expedia, Priceline, Hotwire, CheapOAir) have fallen out of the top 10 entirely. Our former top two websites slipped to #6 and #7. The third-place holder is occupied not by a website but by a smartphone app. And a relatively new site debuted near the top of the heap in the #2 spot.
A Word on Methodology
We tested 19 sites on the same 28 itineraries. We tried both last-minute flights (leaving the coming weekend) and APEX fares (booked six weeks out). We covered major gateways (NYC to LAX, Miami to Rio) and secondary ones (Philadelphia to Rome). We threw in a curve ball (Denver to New Delhi) and even included a flight with no North American legs (London–Barcelona) to see how well each contestant handled Europe‘s wilderness of low-cost carriers.
We have no time for, um, “creative” itineraries that would be hell to fly—so we discarded results that increased total travel time by more than half through excessively long layovers, too many stops, or flying way out of the way just to change planes. Airlines may think such routings make for viable plans, but we don’t.
We then used a complicated, weighted scoring system for each route search that rewards two points to any site that finds the best fares, one point for second-best, nothing for average results, a negative point for high prices, and minus two for the sites that returned the worst fares. Fares within 1% of one another were considered equal.
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What our terms mean
There are a few things to keep in mind before you search for airfare.
An aggregator is only as good as the OTAs it canvasses. There are booking engines (Booking.com, Expedia, Priceline, etc.). And then there are aggregators—sites that do not book tickets but instead search dozens of booking engines, airfare sites, and OTAs (online travel agencies) and compile the results in one place; you then click through to the one of your choice to make the actual purchase.
Some of the booking sites these aggregators show you are better than others. As with any unfamiliar company, always do a quick BBB.org check and a search for complaints to find any red flags. Also, some OTAs are prone to dangling lead prices a few bucks below what they will actually offer once you click through to the site, and some misleadingly categorize “direct” flights—which do actually stop, but do not require you to change plane—as “non-stop.” Even the best OTA may sometimes accidentally direct you to a site that posted inaccurate prices, and these OTAs may come and go before aggregators realize they should be eliminated from the roster.
You must search Southwest.com on your own. Southwest annoyingly does not allow its results to be aggregated or sold through third party OTAs. However, given Southwest’s consistently low fares, free luggage, and generous change policies make it well worth the additional step of searching it directly.
The 10 Best Airfare Search Sites
#1: FareArena
Aggregator
FareArena is back on top this year, leapfrogging from #3 to become the hands-down best performer on price. It was the only service on the list never to stumble below average on any fare—and when it was average, it was often only $10 to $15 higher than the cheapest rate. It found the best or near-best airfare a whopping 13 times out of 28. We suggest never booking a ticket without checking FareArena first.
It was the only service that managed to find a last-minute direct flight between JFK and LAX. (Everyone else wanted to force us to make at least one plane change—and still charge $97 more.) FareArena was also one of the first aggregators to include low-cost airlines, and still innovating by displaying the star rating for all third-party booking sites (along with how many users rated it), which really helps with vetting unfamiliar OTAs.
What catapulted FareArena to the top was its skill at ferreting out low fares on just three days’ notice. Add to that decent filters, a pricing calendar and graph, and the ability to include nearby airports and search for destinations in an entire country rather than just a city. You can even type “Everywhere” in the destination field for a list of the cheapest fares to many popular destinations from your departure airport.
In 2023, it added a separate feature, the Savings Generator, which tracks prices from 76 airports to 15 of the most popular destinations and tells you how far ahead to book, and on which day, for the best rates. The data isn’t bundled into the main search function, however; you will find that advice at about.FareArena.com.
Pros: The champion for lowest fares; shows a whole month of fares on a calendar; can search nearby airports; shows which airline operates a codeshare flight; can find lowest fares to many destinations at once; fare alerts
Cons: Doesn’t include baggage fees up front (but does maintain a page of links to each airline’s fees page); mixes sponsored results with organic ones, even though it marks them clearly.
#2: Skyscanner
Aggregator
Skyscanner is back on top this year, leapfrogging from #4 to become the hands-down best performer on price. It was the only service on the list never to stumble below average on any fare—and when it was average, it was often only $10 to $15 higher than the cheapest rate. It found the best or near-best airfare a whopping 13 times out of 28. We suggest never booking a ticket without checking Skyscanner first.
It was the only service that managed to find a last-minute direct flight between JFK and LAX. (Everyone else wanted to force us to make at least one plane change—and still charge $97 more.) Skyscanner was also one of the first aggregators to include low-cost airlines, and still innovating by displaying the star rating for all third-party booking sites (along with how many users rated it), which really helps with vetting unfamiliar OTAs.
What catapulted Skyscanner to the top was its skill at ferreting out low fares on just three days’ notice. Add to that decent filters, a pricing calendar and graph, and the ability to include nearby airports and search for destinations in an entire country rather than just a city. You can even type “Everywhere” in the destination field for a list of the cheapest fares to many popular destinations from your departure airport.
In 2023, it added a separate feature, the Savings Generator, which tracks prices from 76 airports to 15 of the most popular destinations and tells you how far ahead to book, and on which day, for the best rates. The data isn’t bundled into the main search function, however; you will find that advice at www.skyscanner.com/tips-and-inspiration/best-time-to-book-savings-generator.
Pros: The champion for lowest fares; shows a whole month of fares on a calendar; can search nearby airports; shows which airline operates a codeshare flight; can find lowest fares to many destinations at once; fare alerts
Cons: Doesn’t include baggage fees up front (but does maintain a page of links to each airline’s fees page); mixes sponsored results with organic ones, even though it marks them clearly.
#3: Kiwi
OTA
The decade-old Czech site Kiwi tells you about several modern travel hacks to create a powerful booking engine: self-transfer between non-partnered airlines, adding buses and trains to the mix, and those hidden city “skiplag” fares (it labels those as a “no-checked-bag itinerary”). It was very close to our top performer on price, although it did return one below-average rate, and it offers plenty of nifty features.
Kiwi caters to flexible travelers. The default departure date is “anytime,” allowing you to see at once which days will be cheapest, and more prices show up on the date-selection calendars. On the results page, a pricing table shows a fare grid for three days to either side of your chosen dates, and a bar graph shows you anticipated prices for a dozen days (you can scroll to see more).
Filters allow you to return from or to a different airport—handy for big cities with multiple choices—and you can add nearby ones. That enabled it to find Newark in our Philadelphia–Rome search, bringing our price down from $5,352 to $1,460—totally worth an 85-mile drive. Kiwi also allows you to recalculate based on bag fees.
Kiwi’s Nomad option is like a virtual travel agent. You select a departure airport, date range, trip length (which also can be a range), and any number of dream destinations and it will create the best itinerary to save time and money. It also offers sample air itineraries (customizable) by continent. For us, one was a suggestion for an 18-day European vacation out of New York City on mixed carriers that included Lisbon, Madrid, Barcelona, Paris, and London, pausing in each for three to four nights, for $1,459. Not bad.
So why isn’t it #1? Well, Kiwi catches some bad customer reviews for lackluster service, especially when something goes wrong. That can happen when any third party airfare seller cobbles together tickets on multiple airlines, so read the terms and conditions carefully (that goes for any site, really).
Pros: Almost the best at finding the lowest fares; can incorporate train and bus options; powerful filters; excellent options for flexible itineraries; “Nomad” multi-city trip-planning feature; can add baggage fees to fares
Cons: Frequently cited for poor customer service; a pop-up Booking.com page of hotels is pre-selected
#4: Hopper
OTA
The travel app Hopper has been around since 2015 and it finally proved it has the goods. Its high ranking is due to finding the best or near-best price 13 times, which was on a par with the top two sites. It could easily have snared a higher ranking save for a few flubs on last-minute long-haul flights—not the worst, but below average.
Hopper has a simple, intuitive, colorful interface. The calendar is color coded to indicate the cheapest travel days for months to come, and when you tap on the info icon of any result, it displays a bar graph scoring that flight based on airline, price, fare class, duration, and stopovers. It doesn’t have as many filters as some other sellers, but it does offer valuable advice on when to book based on price trends. We also like the in-depth info for each flight, including seat pitch, baggage regulations and fees, and which amenities cost extra.
The constant come-ons to join its Carrot Cash member program are a bit annoying, and Hopper does make you click through several hard-sell screens for add-ons (insurance, cancellation coverage, flexible ticket options) before getting to the booking page, but you can easily ignore these infractions.
Pros: Consistently decent fares; excellent breakdown of flight amenities; fare alerts; advice on whether to buy now or wait based on price trends
Cons: Limited filters; lots of pop-up pitches; no website version.
#5: Kayak
Aggregator
Kayak is probably the most famous airfare aggregator but, frankly, its results were mostly middle-of-the-road. On the positive side, it has amongst the most complete set of filters, including obscure ones like landing times, layover cities, alliances, in-flight amenities, and aircraft type. Kayak is also one of only three sites to include a filter that allows you to factor in any number of checked and cabin bags. Beyond that, it falters.
It did find a low price on Miami–Rio by puzzling together a “hacker” fare of two one-way tickets rather than a round-trip one. Then again, on a last-minute Philadelphia-to-Rome flight, it turned up a fare that was more than twice as expensive as it needed to be (as did its corporate siblings, Momondo and Booking, lower in our ranking).
Interestingly, though, Tripadvisor found the best fare one time more often than Kayak could. Kayak further tipped the scales in its favor by performing above average more reliably. It nabbed “second-best” rates seven times compared to to Tripadvisor’s three.
Kayak has inexplicably removed a handy feature that it was one of the first to offer years ago: a “Flex Search” option that checked fares up to three days on either side of your dates. Why would it remove that handy feature, especially when much of the competition has adopted something similar?
Pros: Fare alerts; excellent filters; can calculate fares with baggage fees; advice on whether to buy now or wait based on historical price trends
Cons: Rarely the best on price; lost some of the great features that once set it apart.
#6: Tripadvisor
Aggregator
Tripadvisor is no longer just a platform to vent about travel mishaps. The granddaddy of crowdsource sites is trying to become a one-stop shop for all your travel needs and, we have to admit, its efforts in the airfare search department have become impressive. Though it slips from #6 last time to the #7 spot, it outperformed the top four when it came to finding the best fare six weeks out.
What held it back was on our last-minute tests, where it was the only service that somehow could not find any direct flights from Miami to Rio or Philadelphia to Rome—which shouldn’t have been hard to do. Nearly everyone else handily came up with direct flights on American Airlines for both itineraries.
It also couldn’t find the shortest layover combo for Denver–Delhi, adding an unnecessary four hours of misery in Chicago on the way home. On its results page, it does suggest searching Southwest, which is useful—but some of its other suggestions were for notorious bait-and-switch agencies that don’t honor initial price quotes.
Pros: Fare alerts; good variety of filters; can be asked to include nearby airports
Cons: Misses obvious possible connections; doesn’t include baggage fees; automatically opens search windows for additional sites unless you deselect the function; adjusting filters sometimes crashed the results and forced us to start over; sometimes suggested hare-brained itineraries not worth the savings.
#7: Momondo
Aggregator
How the mighty have fallen. Momondo debuted at the #1 spot in our rankings in 2006, where it remained until 2019, when it slipped to #7. But now? We can only surmise that it lost its drive of constant innovation after Booking Holdings acquired it in 2017.
To be fair, there is very little difference in the raw data score for all the sites in the middle of the pack here. Momondo actually scored the best price of any site six times, and it only dipped below the average rates once. That was on the Philly–Rome trip, for which it wanted to charge more than double what the top-performing sites did (a dishonor it shared with its corporate siblings, Booking and Kayak). But all in all, it was average.
Momondo has also transitioned from pure aggregator to an OTA as well, offering direct booking on its own site. It is admirably transparent about this: When you click the menu for any deal, it displays its own price first, but it also includes fares from other sites, even if they’re cheaper.
Its filters are among the most complete in the business, and its results screen remains one of the most complete—though it would be nice to include actual baggage fees, rather than generic notes like “baggage fees may apply.”
Pros: Decent results overall; fare calendar graph shows average rates for a wide range of dates; supplies “when to buy” advice; “Flight insight” feature offers intel on your searched city pair (like the cheapest and most expensive average fares, time of departure, day of the week, and more)
Cons: Results were merely average 57% of the time; no baggage fee disclosures; you need to check for consumer complaints before purchasing from some of the unfamiliar third-party vendors it finds.
#8: Skiplagged
Aggregator
Skiplagged, an upstart that first appeared in 2013, fast outgrew its travel hacker roots to claim the top spot in 2019. How did it fall so far in the rankings this time? For one thing, our new #8 (and others) have also adopted Skiplagged’s main trick of using “hidden city” fares, a somewhat shady savings technique the airlines hate—it involves buying itineraries that have stops and abandoning some flight legs before the final destination. Using hidden city fares might be cheap, but it means you can’t check luggage.
More significantly, it has slipped to being merely average on price. Skiplagged did find the best rates a few times on last-minute fares, but it batted below average on transatlantic fares even when we looked six weeks ahead.
More criticisms: Some of the seemingly low fares it finds from questionable OTAs can actually be higher than the competition once you click over and price them out. Skiplagged also lacks robust filters, doesn’t disclose baggage fees, and rounds down all the prices—that last complaint is minor since we’re only talking about a few cents, but just feels sneaky.
Pros: It’s pretty fast; has that “hidden city” feature
Cons: Mediocre filters; no flexible dates option (though it does have a graph indicating prices over 30 days); shows each leg of an itinerary separately, so you have to keep selecting legs until you can see a total price; doesn’t display baggage fees; still sells optional “skiplagged” results that airlines have sued passengers for using (but you can disable seeing these by unticking the “Hidden City” option)
#9: Google.com/travel/flights
Aggregator
Google’s purchase of the IATA Software flight engine a decade ago didn’t turn into the game-changer many predicted. However, the titan of online search has combined that database with its own algorithmic wizardry to produce some excellent features.
First of all, it is unbelievably fast, refreshing results as you key in filters almost before you can blink. It shows average prices on a pop-up calendar so you can see at a glance when the cheapest days to fly are for the next two months (you can also peruse a price grid and price graph on the results page). And it’s one of only three engines in our results that has a filter allowing you to add checked and cabin bags and recalculate the prices accordingly.
Google Flights features a fabulous “Explore map” feature that allows you to select any two major city pairs and see lowest fare for your dates in addition to price trends for the month surrounding them. It also went above and beyond by suggesting we try leaving from Newark instead for our proposed Philly-to-Rome trip—which in a pricey last-minute situation would have been well worth the drive, as it brought the fare down from $5,265 to just $1,055.
So why is the mighty Google sitting at #9?
It simply never found the best price. Not even once. It whiffed on the Denver to Delhi route every time, and was the only site not to figure out that you could pair Vueling and Easyjet flights to make a last-minute London–Barcelona trip cheaper. It also frequently found the exact same flight as many other sights, but at prices that were a little bit higher—often just 5% to 15%, but still.
Pros: Handily the fastest; better than most at canvassing low-cost carriers, but with gaps; useful calendar and graph of prices; detailed filters; ability to include or exclude airlines or connecting airports from results; names in-flight amenities (seat outlets, entertainment, Wi-Fi)
Cons: Performed only average on price—never the best, and sometimes the worst
#10: Booking.com
OTA
Yes, that Booking.com. The one famous for hotels. It added airfare searches a while back, and although it debuted at #7 a few years ago, it has since slipped to the last place in our top 10.
Booking.com is a corporate sister of Kayak, yet their inventory wasn’t the same. The two differed so much that both earned separate places. Case in point: Kayak (coming later on this list) turned up the cheapest last-minute fare of any company on our tricky Denver-to–New Delhi route, but Booking.com came up with the most expensive quote. On the other hand, give Booking six weeks’ notice for the same route and it will actually perform a bit better than average. On the third hand, that was the only search where Booking performed better than average. For all the others, its performance was just so-so. Maybe it should have stuck to hotels.
Pros: Dead simple interface; speedy results
Cons: Rarely does better than middling on price; does not show baggage fees