How we make this list: we compare pricing pages, product documentation and public user reviews. Ratings come from G2, Capterra or Trustpilot, with the date we checked them.
Key takeaways
- Google Flights is the best free starting point for comparing fares across airlines and dates.
- Skyscanner and Kayak give the broadest fare search, including flexible dates and nearby airports.
- Hopper adds price predictions and fare freezing for travelers who want timing guidance.
- Booking directly with the airline after comparing fares usually gives the best change and refund options.
Quick comparison
| Tool | Best for | Starting price | Free plan |
|---|
 Google Flights | Fast fare comparison | Free | Yes |
 Skyscanner | Broad fare search | Free | Yes |
 Kayak | Flexible search and alerts | Free | Yes |
 Hopper | Price predictions | Free | Yes |
 Expedia | Flights plus hotels | Free | Yes |
 Momondo | Cheap fare discovery | Free | Yes |
 CheapOair | Discount fares and support | Free | Yes |
 Going | Mistake fares and deals | See website | Free trial |
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The best flight apps
Starting priceFree
Free planYes
Google Flights is the fastest way to compare fares. Enter a route and dates, and the date grid and price graph show cheaper days at a glance, which often saves more than any coupon. Price tracking sends alerts when a fare you watch changes, and the explore map helps flexible travelers find cheap destinations from their home airport.
Google Flights mostly links out to airlines and booking sites rather than booking every fare itself, and some budget airlines do not appear, so a fare found elsewhere may beat it. For most travelers, though, Google Flights is the best first search, and booking the winning fare directly with the airline gives the strongest change and refund terms available.
What we like- Very fast results
- Date grid and price graph
- Tracks prices with alerts
Watch out for- Does not book every fare directly
- Some budget airlines missing
Starting priceFree
Free planYes
Skyscanner searches a wide range of airlines and online travel agencies, which helps find fares that a single airline site would miss. Its "everywhere" search suits flexible travelers, showing the cheapest destinations for a given month, and whole-month views reveal cheaper travel days quickly for any route. Price alerts track routes you care about without daily manual checks.
Booking happens on partner sites, so the final experience, fees, and change policies depend on the seller, not Skyscanner. Check the seller reputation and total price, including baggage fees, before paying. For broad discovery and flexible-date searching, Skyscanner remains one of the best free tools available.
What we like- Searches many airlines and booking sites
- Flexible "everywhere" search
- Good price alerts
Watch out for- Booking happens on partner sites
- Fare quality varies by partner
Starting priceFree
Free planYes
Kayak combines flight search with strong filters, letting travelers narrow by stops, times, airports, baggage, and airline. Its price forecast offers guidance on whether to book now or wait, and fare alerts track changes over time. Kayak also covers hotels and rental cars, which suits travelers planning a whole trip in one place.
Like Skyscanner, Kayak often hands booking to partners, so seller quality varies and the total price can differ from the headline fare. Its feature set also overlaps heavily with Google Flights, so many travelers use one or the other. For travelers who want deep filters and a full trip planner, Kayak is a strong choice.
What we like- Strong filters and fare tools
- Price forecast guidance
- Good for hotels and cars too
Watch out for- Partner booking quality varies
- Some features duplicate Google Flights
Starting priceFree
Free planYes
Hopper stands out for price predictions. It analyzes historical fare data to advise whether to book now or wait, and its color-coded calendar shows cheap and expensive days clearly. Fare freeze lets travelers lock a price for a period while they decide, which removes the pressure of a fare jumping overnight.
Predictions are estimates, not guarantees, and fares can move against the forecast, so treat advice as guidance rather than a promise. Some features, such as fare freeze and disruption protection, carry fees. For travelers who stress over timing a purchase, Hopper gives the most useful timing guidance of any free app.
What we like- Price predictions and "book now or wait" advice
- Fare freeze option
- Good mobile app
Watch out for- Predictions are estimates, not guarantees
- Fees apply to some features
Starting priceFree
Free planYes
Expedia suits travelers who book flights and hotels together, since packages often cost less than booking each part separately. Its rewards program returns value on future trips, and the app covers flights, hotels, cars, and activities in one place. Package filters help compare total trip costs rather than flight prices alone.
Change and cancellation policies depend on the fare and hotel rules, and resolving problems through an agency can be slower than dealing with the airline directly. For a bundled trip, Expedia often wins on total price. For a flight-only booking where flexibility matters, booking direct with the airline is usually safer.
What we like- Bundles flights with hotels and cars
- Rewards program
- Good package deals
Watch out for- Change policies depend on fare rules
- Service can be slower than booking direct
Starting priceFree
Free planYes
Momondo, owned by the same group as Kayak, searches many booking sites including smaller agencies that larger search tools miss, which sometimes surfaces very low fares. Its interface is simple, and flexible-date views help travelers shift days to save money. For bargain hunters willing to compare sellers carefully, Momondo is worth checking alongside Skyscanner, especially for international routes where small agencies sometimes undercut larger sellers by a wide margin.
Partner quality varies widely, and the lowest fare may come with strict change rules, high baggage fees, or a little-known agency, so read the total price and terms before paying. For travelers who prioritize the lowest fare and accept that trade-off, Momondo earns its place.
What we like- Searches many small booking sites
- Often surfaces very low fares
- Simple interface
Watch out for- Partner quality varies widely
- Low fares may carry strict terms
Starting priceFree
Free planYes
CheapOair focuses on discount fares, with promo codes and deals that sometimes beat standard search results. Phone support suits travelers booking complex multi-city itineraries who want a person to confirm details, and the app covers flights, hotels, and cars. That human help is a real difference from pure search tools.
Service fees apply, and change policies vary by fare, so the final cost and flexibility need careful reading. For a simple domestic flight, a free search tool plus direct booking is usually cleaner and faster. For a complex itinerary or a traveler who wants phone support, CheapOair gives useful help.
What we like- Discount fares and promo codes
- Phone support
- Good for complex itineraries
Watch out for- Service fees apply
- Change policies vary by fare
Starting priceSee website
Free planFree trial
Going, formerly Scott's Cheap Flights, watches for mistake fares and unusually cheap deals from your home airports and emails them to members. Those deals can cut international fares dramatically, but they need fast action, since mistake fares often disappear within hours. Premium membership adds more alerts and faster notifications.
Going does not replace a search tool, since it only alerts you to deals rather than searching any route on demand, and free alerts are limited. For a flexible traveler with a home airport and a travel wish list, Going is the best deal-finding service on this list. Pair it with Google Flights for planned trips, and keep your passport validity and travel dates flexible where possible.
What we like- Finds mistake fares and rare deals
- Email alerts for your home airport
- Good for flexible travelers
Watch out for- Deals need fast action
- Premium membership for full alerts
How we chose
We compared vendor pages, product documentation, and public user reviews, and we judged each app on fare coverage, search flexibility, price alerts, booking experience, fees, and extras. Free apps were judged on what they do without payment, and paid features were judged on whether they add real value. We did not claim hands-on testing. Fares change constantly, so no tool guarantees the lowest price on every route, and the best practice is to compare two or three tools before booking.
What to check before you pick
Start with your trip type. A simple domestic flight needs only a good search tool and direct booking, while a flexible international trip benefits from deal alerts, flexible-date views, and price predictions. Check the total price, including baggage, seat selection, and booking fees, because headline fares often hide those costs, especially on budget airlines.
Also check the seller before paying through a third party, since change and refund help depends on who sold the ticket. Check cancellation policies, especially for non-refundable fares, and consider travel insurance for expensive or complex trips. Finally, set price alerts early, since fares for popular routes move weeks before departure, and early alerts give you time to act rather than panic-buy. Also check passport and visa rules well before booking an international trip, since a cheap fare is worthless if you cannot board, and check whether your fare includes a checked bag, a carry-on, and seat selection, or whether those basics will be added at the airport at a much higher price. Travelers who fly the same route often should also compare loyalty value, since a slightly pricier fare on your usual airline can earn status and perks worth more than the saving.
Frequently asked questions
Which flight app finds the cheapest fares?
No single app wins every route, so compare Google Flights, Skyscanner, and Kayak for planned trips, and add Going alerts for deals. The cheapest fare often comes from shifting dates or nearby airports, which all three search tools show clearly.
Should I book through an app or directly with the airline?
Booking directly with the airline usually gives better change, cancellation, and disruption help, while third-party sellers can be slower to resolve problems. If you do book through an agency, save every confirmation, receipt, and fare-rule screenshot, since those records decide disputes when a flight changes or cancels. Compare fares first, then book direct when the price is close, and use an agency only when the saving is large or the itinerary is complex.
Are Hopper price predictions reliable?
Hopper predictions are data-based estimates, not guarantees, and fares can still move against the forecast. Use them as timing guidance alongside price alerts, and book when the fare fits your budget today rather than waiting endlessly for a predicted drop that may never arrive.
What is a mistake fare?
A mistake fare is a ticket priced far below normal due to an airline or agency error, such as a missing digit or wrong currency conversion. Airlines sometimes honor them and sometimes cancel them, so book quickly, wait before making non-refundable plans, and read Going alerts promptly.
Do flight apps include baggage fees?
Most search tools show baggage information, but the final baggage cost depends on the airline, fare class, and route. Check the airline baggage page for your exact fare before booking, especially on budget airlines where baggage fees can exceed the ticket saving itself.
Sources we checked (8)
- https://www.google.com
- https://www.skyscanner.com
- https://www.kayak.com
- https://www.hopper.com
- https://www.expedia.com
- https://www.momondo.com
- https://www.cheapoair.com
- https://www.going.com
Is your product missing or out of date?
We review this list regularly. Vendors can request a listing, send updated pricing or ask about featured placement.
Shihab Mia · Founder, Rankite
Shihab has 5+ years in B2B and SaaS SEO. He writes Rankite's software buying guides from pricing pages, documentation and public user reviews. More about Shihab.