How to find cheap flights

The cheapest flights are found by being flexible: search a whole week or month instead of fixed dates, try nearby airports, and set a price alert if you are not ready to buy. Compare fares on a flight search site such as Google Flights, Skyscanner or Kayak, then usually book with the airline itself. Before you pay, add up the bag and seat fees, because a low fare on a budget airline can end up costing more than a full-service ticket.

This guide explains each step using the tools’ own help pages and the official passenger rights rules in the EU and the US, as checked in October 2026. For a ranking of the search tools, see the 5 best flight search sites.

Be flexible on dates and airports

Google’s own tips note that flight prices often change by day of the week, so the same route can cost very different amounts a day apart. Every major search site has a way to see that at a glance:

• Google Flights shows a calendar with the lowest total price to fly on each day, plus a price graph to explore fare trends by week or month. Its help pages note that prices in this view are updated about once every 24 hours.
• Skyscanner has a Whole Month search: pick Flexible dates and a month, and it shows the cheapest days to fly. Skyscanner says these figures are estimates based on searches from the last eight days, so confirm the live price.
• Kayak lets you search plus or minus 3 days around your chosen dates, and its color-coded Price Calendar marks the cheapest days in green.

Airports matter as much as dates. Google Flights lets you enter several airports separated by commas, and Kayak has an “all airports” option for cities with more than one. A cheaper fare into a secondary airport is only a saving once you add the cost and time of getting into town.

If you do not mind where you go, use an “anywhere” search: Skyscanner’s Everywhere search lists destinations from your home airport sorted by price, and Kayak and momondo have an Explore map where you enter a budget.

Set price alerts instead of checking every day

If you are not ready to book, let the tools watch the fare for you:

• Google Flights emails you when the price of a tracked flight or route changes significantly. Tracking “Any dates” emails you when the route’s lowest price for a month drops.
• Skyscanner Price Alerts notify you when the fare on a route you searched rises or falls. You set one with the bell icon on the results.
• Kayak emails you when the price of a flight you toggled a Price Alert on changes, and on some routes shows a Price Forecast such as “book now” or “wait”.

Set alerts on two or three tools at once. They draw on different sources, so one may spot a drop the others miss.

Photo by Erik Odiin on Unsplash

Compare on a search site, then book direct

Flight search sites, also called metasearch engines, compare prices but most do not sell you the ticket. Google Flights says you will “usually be taken to the airline’s website or online travel agency” to finish the booking, and that it works with more than 300 airline and travel agency partners. Skyscanner says it “is not a travel agent”, and Kayak says it “doesn’t sell or process your tickets or reservations”.

When the airline and an online travel agency show similar prices, booking with the airline is usually simpler if something goes wrong. The US Department of Transportation explains why: the company that appears on your card statement, called the “merchant of record”, is the one responsible for issuing refunds when they are due. If you bought through a travel agent, you may be dealing with the agent for the ticket refund but with the airline for a refund of bag fees, which DOT says ticket agents are not responsible for.

Whoever you book with, check the passenger names against your passports before paying. DOT notes that airlines are not required to correct a misspelled name for free.

Count the bags and seats before you compare

The headline fare is rarely the full cost. Google Flights’ help page says plainly that additional fees may apply for things like baggage and credit cards, and that each airline has different baggage rules and fees. Google Flights has a filter for prices with bag fees, and Kiwi.com lets you filter by number of bags, so the prices you compare are closer to what you will pay.

Budget airlines make this especially important. As of October 2026, Ryanair’s bag policy includes one small personal bag (40 x 30 x 20 cm) on every fare, which must fit under the seat in front of you. A 10kg cabin bag for the overhead locker comes with its paid Priority option, and checked bags of 10kg, 20kg or 23kg are extra. Other low-cost airlines have their own sizes and prices, so read the bag page of the airline you are actually flying.

A fair comparison looks like this:

What to add	Why it matters
Cabin bag	Often not included on the cheapest fares
Checked bag	Check the price for each direction of a return trip
Seat selection	Needed if you want to sit together
Card or payment fees	Some sellers add these at checkout
Transport to the airport	Secondary airports can be far from the city

Budget airline and self-transfer rules

Low fares come with stricter rules. Read the fare conditions for change fees, refund terms and check-in requirements before you book, and measure your bag against the airline’s limits, not your memory of the last trip.

Be careful with self-transfer itineraries, where a search site combines separate tickets from different airlines. Google Flights says that these separate tickets require you to check each price and buy each ticket individually. Kiwi.com, which builds many of them, explains on its own Guarantee page that because a self-transfer is not an official itinerary, carriers are not obligated to provide replacement flights if a disruption makes you miss your next flight. Leave long connections, and consider whether any protection the seller offers is worth it.

When to book

No search tool can promise the lowest price on a given day, and honest ones say so. What they offer is guidance based on their own data:

• Kayak advises booking as early as you can for peak periods such as summer and Thanksgiving, and shows a Price Forecast on routes where it has enough data.
• Google Flights shows a tip such as “Prices are less than usual” when a fare is well below what similar trips have cost.
• Skyscanner’s Savings Generator suggests how far ahead to book for a route.

For flights to, from or within the US, there is also a safety net. DOT requires airlines, for tickets bought at least seven days before departure, to either let you cancel within 24 hours for a full refund or let you hold the fare for 24 hours without paying. Airlines may offer one or the other, so check which before you buy.

If your flight is cancelled

Your rights depend on where you fly and with whom. Here are the two rule sets most travellers meet, as described on the official EU and US government sites in October 2026.

	EU rules (Regulation 261/2004)	US rules (Department of Transportation)
Which flights	Flights within the EU, flights leaving the EU, and flights into the EU on an EU airline	Flights by airlines covered by DOT refund rules
Your choice	Refund, re-routing as soon as possible, or re-routing at a later date	Refund if you choose not to travel or not to accept credits or vouchers
Care while you wait	Meals, refreshments, a hotel if needed, and transport to it	Depends on the airline’s own customer service commitments
Cash compensation	EUR 250, 400 or 600 depending on distance, unless you were told more than 14 days ahead or the cause was extraordinary	Not required by the refund rule
How refunds are paid	Refund of the ticket	Automatic refund within 7 business days (card) or 20 business days (other payments) when you bought directly from the airline

Under the EU rules, extraordinary circumstances that cancel compensation include air traffic control decisions, severe weather and security risks, but the EU site says most technical problems and the airline’s own staff strikes do not count. Keep receipts for meals or a hotel if the airline does not provide them.

Under the US rules, a “significant change” also entitles you to a refund if you decline it, for example a departure 3 or more hours earlier or an arrival 3 or more hours later on a domestic trip (6 hours for international), a different airport, or more connections. If you accept a rebooking or fly on the changed flight, you are not entitled to a refund under DOT rules.

Once the flight is booked, the next big cost is usually the room. Our guide on how to book hotels without overpaying covers cancellation rates, fees and price matching.