There are numerous ways to search for flights online, from legacy online travel agencies (OTAs) like Expedia and Orbitz to a host of newer OTAs and flight search engines that have popped up in recent years, like Hopper.
Despite the plethora of options, there are a few OTAs and metasearch sites we routinely recommend because they have the best tools and typically unearth the best fares. Here, we break down the most popular flight search sites and OTAs and give you our take on each, plus some tips on when to use each one depending on your flight search needs.
Google Flights is one of the most comprehensive and user-friendly flight search engines around, offering plenty of features to fine tune your selections. It’s also great for exploring flight options for a range of destinations if you’re not set on traveling to one specific place. We frequently include Google Flights search results in our deals, and we often recommend travelers start their search on Google Flights—particularly if they have flexible dates or locations.
Why we love it:
Google Flights makes finding great deals easy with features like a map to explore prices from your home airport to destinations across the entire world, a low-price calendar to help you find the cheapest flight if you have flexibility with dates, and a multi-city search function so that you can check for the best prices between 7 origin airports and 7 destination airports at one time. The search engine has an easy-to-use interface that displays straightforward results.
While Google Flights is pretty comprehensive, it sometimes misses the cheapest fares, as it pulls its data from the airlines (though there are some absences like Southwest, Aeromexico, and Hong Kong Airlines, the latter two of which don’t show up in the calendar of fares) and major OTAs, but excludes smaller OTAs.
>> Read our guide to using Google Flights or find out how to use Google Flights and Kayak together.
Skyscanner is a UK-based flight search engine that’s ideal for people with flexibility in their travel plans, as you don’t need to search for flights from or to specific destinations. Instead, you can choose an origin as broad as an entire country and a destination as broad as “everywhere.” Skyscanner redirects users to book through the airlines or an OTA.
Why we love it:
Skyscanner’s “Everywhere” tool makes it easy to find the best deals over specific travel dates if you’re flexible with your destination. Similar to Google Flights, there’s also a flexible date calendar if you’ve already picked your destination, plus a multi-city search function to find the best deals for a given area. Skyscanner also has a great mobile app for searching on the go.
Like many flight search engines, Skyscanner sometimes misses the lowest price because it doesn’t search every OTA. Prices sometimes ghost, too, which means that even though a low price is displayed on Skyscanner’s results page, when you go to book, that price is no longer available (this also happens occasionally on Google Flights). Additionally, the monthly calendar does not live-update, rather it’s based on users’ searches, so while it displays accurate pricing for dates on popular routes, it may not show updated info for less-searched routes.
>> Read our guide to using Skyscanner.
Momondo is a flight search engine that pulls data from numerous OTAs, including lesser-known ones that sometimes offer the best deals, which means it often (though not always) unearths the best prices. As with other flight search engines, you don’t book directly through the site but are redirected to an OTA or airline.
Why we love it:
Since Momondo searches many smaller OTAs as well as the larger ones, you’re often able to find better deals than the ones that show up on Google Flights or major OTAs like Expedia or Priceline.
While Google Flights and Skyscanner return results almost immediately, Momondo is much slower—prices often take more than 30 seconds to appear. This is because the site is searching hundreds of OTAs at once. Momondo also lacks extra search features, so while it’s great for finding the lowest prices between specific cities on specific dates, there’s no way to search multiple dates or multiple locations. For this reason, we often recommend starting on Google Flights or Skyscanner and then double-checking prices on Momondo.
>> Read our guide to using Momondo.
Kayak is not only a flight search engine, but also a hotel, cruise, and car rental search engine, so it’s great if you’re looking to book several parts of your trip on one site. You can also search for airfare and hotel packages for great bundled deals. All bookings are done via third-party sites—either through the airlines or on an OTA.
Why we love it:
Kayak searches a vast number of OTAs, so you’re likely to find great deals from smaller agencies. Plus, you can easily book hotels and car rentals via the same site, making planning a trip quite easy. It also has a flexible date function and “explore” options that help you pick destinations based on price, trip duration, or even theme (like a romantic getaway). And, like all the others, you can set fare alerts on Kayak.
Like Momondo, Kayak is a slower search engine, which can be frustrating to many users. It also doesn’t have the most intuitive interface, and there are advertisements that can muddy the experience. While Kayak searches many OTAs, it does skip a few, so you might ultimately be able to find cheaper tickets via another search engine such as Momondo.
>> Read our guide to using Kayak.
Priceline is a true OTA, meaning that all of the deals offered will be booked directly through the site. It searches flights, hotels, car rentals, cruises, and vacation packages for travelers.
Why we love it:
Priceline’s interface very clearly states pricing and cancellation information and it offers a Best Price Guarantee, so if you find a better deal elsewhere, even after booking, Priceline will refund you the difference. Its Express Deals can save you quite a bit on flights, if you’re willing to book without knowing all the details (like exact flight time and airline) and Priceline has one of the better cancellation policies, allowing you to cancel or change your flight for free until 11:59 PM ET the next business day on many flights.
There are limitations to Priceline’s search features—you can’t search multiple cities and flexible dates are restricted to a three-day window (one day before and one day after your search dates). You also can't book direct with airlines, which many travelers prefer to do.
>> Read our guide to using Priceline.
Skiplagged is a search engine for hidden city fares, which is when travelers book connecting flights that go one point beyond their final destination and skip the last flight to stay in the layover city. These fares can often be cheaper than booking direct flights between the origin and destination. (e.g. flights from A to B can be more expensive than flights from A to C with a layover in B.)
Why we love it:
Skiplagged is a great tool for travelers whose destination is a hub airport that is a common layover point. No other search engine or OTA searches for hidden city fares, which can sometimes be much cheaper, especially at the last minute.
While technically legal, there are many caveats to booking hidden ticket fares. For instance, you typically won’t be able to check a bag, since the bag will end up in the final city on the itinerary, not the layover city. Additionally, once you skip a leg, all subsequent flights on your itinerary will be cancelled, so you need to book two one-ways, or only skip the final leg of your journey.
>> Read our guide to using Skiplagged.
ITA Matrix is a flight search engine developed by MIT computer scientists and currently owned by Google—it’s the tool that powers many other flight search engines, including Google Flights. It’s an ideal product for travelers who have very specific flight demands and are tech savvy.
Why we love it:
If you have hyper-specific search parameters (specific airlines, routes, times, price per mile, or layover cities, for instance), this is the search engine for you. You can input any number of codes that whittles down the options to exactly what you’re looking for.
ITA Matrix is a complicated tool with a confusing interface, meaning it’s not ideal for the average user. It’s better for frequent, tech-savvy travelers who need very specific flights and don’t want to wade through irrelevant options.
>> Read our guide to using the ITA Matrix.
Orbitz, Expedia, and Travelocity
Orbitz, Expedia, and Travelocity are all OTAs that belong to the same parent company (Expedia Group). They’re all very similar products that offer deals for airfare, hotels, car rentals, and vacation packages that are all bookable directly on the sites. Because they’re all part of the same group, they have similar features and typically return the same results.
Why we love them:
Orbitz, Expedia, and Travelocity are great one-stop shops for vacations as they make it easy to bundle flights, hotels, and car rentals into one booking. Orbitz and Expedia also have rewards programs, so loyal users can earn points and save.
All three OTAs are not as robust as the other sites on this list. There’s limited ability to search multiple cities and dates, so you might not be able to see all your options at the best prices. But if convenience is key, they might be a good option for you.
Each of the above flight search engines and OTAs has its own pros and cons, so we generally recommend pairing your favorite with one that makes up for the other’s shortcomings. For example, we often recommend flexible travelers start on Google Flights to find the cheapest dates for their trip or find the cheapest destination for their dates, and then cross-reference that search on Momondo to find the lowest fares.
When we send deals to our members we do the legwork for you and let you know exactly which site to use for your search; we even send a link to a sample search to get you started. In short, there’s no one perfect all-in-one search engine, but a combination of the above can help you unearth great deals.