Flight Booking

How to Find Cheap Flights in 2021: The Ultimate Guide

By
Scott Keyes
|
Founder & Chief Flight Expert
June 8, 2021
|
6 min read

Airfare pricing is extremely complex, with algorithms changing fares minute by minute. It puts the average consumer at a significant disadvantage and far too often results in travelers overpaying for flights.

That's why I started Scott's Cheap Flights. After I snagged the fare of a lifetime—$130 roundtrip to Milan—I wanted to help others explore the world for less. Today, my team and I spend hundreds of hours every week searching for cheap flights, and when we find them, we let our members know. We also publish guides like this so that whether you book one of our deals or search for flights on your own, you never overpay again.

Here's how to find the cheapest flights to anywhere in the world.

1. Pick your destination and dates based on price

This is the way most people approach getting a flight:

  1. Pick where they want to go
  2. Pick their dates
  3. See what prices are available

Typically this results in high prices.

Instead, if getting a cheap plane ticket is your priority, flip that approach:

  1. See what prices are available via Google Flights, Momondo, etc. to various places are around the world
  2. Decide which of the cheap destinations appeal to you
  3. Select the dates you like that have cheap fares available

Be flexible with where and when to go. If you’ve picked out your destination, picked out your dates, and don’t have flexibility, 95% of what you can do to bring down the cost of airfare is already out the window. Flexibility is king. Plus, as we'll discuss below, once you get to Europe or Asia or wherever, it’s really easy to hop a budget flight to your final destination.

Sidenote: If you're looking to book the cheapest flights, be sure to search more than one date. (Clicking the calendar in Google Flights shows you cheap fares for two months at a time.)

2. Use the best flight search sites

Our three favorite tools to search for flights are Google Flights, Priceline, and Momondo. There are also some more complex ones like the ITA Matrix, SkyScanner, and various plugins, but for most folks Google Flights, Priceline, and Momondo are plenty.

Remember that Southwest doesn’t show up on search engines and OTAs, so check directly on their website.

>> Read our guides to finding cheap flights with Google Flights, Momondo, or Kayak

3. Find the cheapest place to fly

One of the reasons we love Google Flights so much is because it makes it really easy to see tons of options. First, you can input up to seven airports in the departure and arrival fields, so if you can fly from any airport on the East Coast to any airport in Ireland, voila, just put in the corresponding airport codes and you can see the route that'll be cheapest.

If you're even more flexible, you can use the Google Flights Explore Map.

Just put in your departure airport and leave the destination open (or select a region like Europe or Asia) and a map will populate with all your options. You can search select dates or browse weekend, one-week, or two-week trips in the next six months.

searching Europe on the Google Flights Explore map


4. See which dates are available

Another handy feature of Google Flights is that it's easy to see if moving your dates can lower the price. When you select your dates, Google Flights will show you two months worth of dates and highlight which ones are the cheapest days to fly based on the length of your trip. Often times shifting the dates by even a day or switching from a six-day trip to seven days can cut the price in half.

using calendar date search on google flights

5. Travel on Tuesday, Wednesday, or Saturday

What are the cheapest days to travel? In general Tuesday, Wednesday, and Saturday are the cheapest days to travel. Friday and Sunday are usually the most expensive days.

6. Focus on crossing the ocean as cheaply as possible

If you want to get the cheapest flights possible, focus on getting the cheapest fares across the ocean, even if it’s not from your home airport or to your ultimate destination.

Two itineraries are frequently cheaper than one. Plus you can stay and explore another city for as long or short as you like.

Here's a personal example: I used to live in Washington DC, but the best ticket I ever purchased was the ticket I mention, above, a Mistake Fare from NYC to Milan for $130 roundtrip.

It was well worth the $20 bus ride up, and I even got to spend the weekend with friends in NYC. If I had insisted on flying to Milan from Washington DC (not NYC) the ticket would’ve been around $800, not the $150 I actually paid.

The next best fare I’ve gotten was from DC to Brussels for ~$250 roundtrip. So nice I bought it twice! Even though I didn’t have that much interest in Belgium, I knew once I was in Europe, I could easily find budget flights to other European countries.

For one trip I bought flights from Brussels to Norway (~$60 roundtrip) and for the other trip I bought flights from Brussels to Dublin (~$80 roundtrip). If I had insisted on flying from DC to Norway or Dublin (without stopping first in Brussels), I would have paid around $750 roundtrip, not the $310 and $330 I actually paid. And I wouldn’t have gotten a day in Brussels to boot! Rome2Rio makes it easy to check out local transport options between destinations.

We call this two-step booking the Greek Island trick and it can save you hundreds.

7. If you're traveling with a group, book one ticket at a time

Let’s say you and your partner want to fly from Seattle to Washington DC. At time of writing, the cheapest nonstop flight was $299 per ticket.

Search result for two passengers from SEA to IAD for $299 each.

But a funny thing happens when you reduce the number of travelers from 2 to 1: the price on the exact same flight drops from $299 per ticket to $199.

Search result for one passenger from SEA to IAD for $199.

This pricing anomaly sometimes occurs because whenever you’re booking multiple tickets, airlines want to put your entire group into a single fare bucket.

(A fare bucket is a fancy term that airlines use to denote not just which cabin you’re in, but also any privileges included with your ticket like whether it’s refundable or if it’s upgrade-eligible. The number of seats available in any given fare bucket isn’t a secret but it takes some digging to find; all we’re typically shown when we search for flights is the lowest ticket price.)

In the above example, Alaska Airlines almost certainly only had one ticket left in the cheapest fare bucket priced at $199. So if you searched for two tickets, the airline would skip over the single $199 ticket and instead only show you fares with at least two seats available, $299 in this case.

But by booking one ticket at a time, you can get the first one for $199 and the second one for $299, paying $498 total rather than the original $598.

Does this work every time? No. But anytime you’re traveling with a group, it’s worth checking if fares are cheaper by buying tickets individually. That’s especially true if you’re traveling with a larger group, because the more tickets you buy, the greater the chance there won’t be enough seats for you all in the cheapest available fare bucket.

If you’re able to successfully use this strategy, call the airline after you book and ask to have the multiple itineraries linked. That way, if there are any changes to your flight, the whole group will be able to stay together.

8. Avoid the peak travel times of summer and the holidays

In North America and Europe, the cheapest time of year to fly is usually:

  • January through mid-May
  • September through early December

The most expensive time to fly is usually:

  • Peak summer: mid-June through mid-August
  • Christmas
  • New Year’s Eve

It will also vary a bit by the specific destination, especially around popular festivals. Fares to Dublin for St. Patrick’s Day or to China for Chinese New Year aren’t cheap.

9. Book within the Goldilocks Windows

There's so much bad info out there about the best time to book a flight, with many people claiming it's Tuesdays at 1pm, or early on Sunday mornings. If I achieve one thing in my brief stint on Earth, it will be to convince travelers to stop believing this nonsense. It’s not true, it won’t help you get cheap flights, and if anything will likely result in you overpaying for your next trip.

The better strategy for snagging discounts on flights is to book within what I call the Goldilocks Windows.

Airfare doesn’t change weekly these days. It changes daily, hourly, sometimes even minute-ly. Neither I nor anyone else can tell you with certainty when (or where) next week’s cheapest fares will pop up.

These days, airfare is set by complex algorithms that account for hundreds of ever-shifting factors, from consumer demand to oil prices to competitor’s prices and beyond. One factor airlines no longer rely on: technological constraints that only allowed them to change fares once a week at a set time.

The bad news: there’s no predictable time or date when flights are cheapest to book.

The good news: cheap flights are popping up all the time. That’s what Scott’s Cheap Flights is for.

Though there’s no set time or date that’s always cheapest to book, there’s still a period when cheap fares are most likely to pop up. I call these Goldilocks Windows.

For domestic flights, the best time to book is normally 1 to 3 months before your travel dates. For international trips, it’s 2 to 8 months prior. If your trip is during a peak travel period (Christmas, summer, St. Patrick’s Day in Dublin) add a couple months to those windows. If you’re traveling during low season it’s more likely cheap fares will pop up closer to departure date, but prices tend to jump in the last month or two before departure, so you don’t want to cut it too close.

>> Read our guides on finding cheap flights for Christmas, New Year's travel, or Spring Break or read about the best time to book a cheap flight

10. Set fare alerts to track specific flights

If you know exactly where and when you want to travel, use a site like Kayak or Google Flights to set an airfare alert and get notified if the fare drops below the current price.

11. For cheap domestic flights, check Southwest Airlines and Skiplagged

If you’re looking for cheap flights in the United States, be sure to search Southwest.com separately since Southwest flights don’t show up on any flight search engines.

You can also find some cheap hidden fares on Skiplagged, but be sure to read up on the basics of hidden city ticketing so you know what you’ll be doing.

12. Consider the pros and cons of budget airlines

Budget airlines get a bad rap and some cases, it's warranted (we're looking at you, Spirit). But not all budget airlines are created equal. Plus, budget airlines can be the best and most economical way for connecting your long-haul flight to your final destination. You may not want to fly a budget airline across the ocean, but when a flight from one end of Europe to the other costs $50, a budget airline flight gets a lot more appealing.

>> Read about the best budget airlines in Asia and Europe.

13. See if it's cheaper to pay in a foreign currency

On foreign airlines, it can sometimes be cheaper if you book using the foreign version of their website and use a foreign currency. It's not full-proof. Sometimes there are no savings and sometimes the savings are so small as to not be worth the effort (as we found when we testing out booking Norwegian flights in NOK), but in other cases you can save a hundred dollars or more, so it's often worth checking. Just make sure you book with a credit card that has no foreign transaction fees.

14. Act fast, especially if it's a Mistake Fare

You found a great fare. How long will it last? It's hard to say for sure! Unless it’s an advertised sale (which usually aren’t that great to begin with), there’s no public end-date on any given fare. The rule of thumb is that the better the fare, the shorter it will last.

In general you shouldn't expect most great fares to last longer than a few days. If it's a Mistake Fare, it could be gone in a few hours, or even minutes.

15. Cancel free for 24 hours

Okay, but how can I act fast enough to snag a great fare if you've got, you know, responsibilities and stuff? Well, there's a handy regulation called the 24-hour rule that says for flights to or from the US, airlines must allow you to cancel free within 24 hours.

So, if you aren't sure you can get time off work, for example, rather than wait to hear from your boss, you could go ahead and book the amazing deal you found before it disappears. If your boss comes back and says you can't go, as long as it's within the 24 hours, you can get a full refund.

Side note: You can also use this trick if you book a flight and the price goes down within 24 hours. Just make sure you book the new flight before you cancel the old one.

16. Use a schedule change to your advantage

Airline schedules sometimes change. And when they do, that presents an opportunity. Under federal law, if an airline cancels or significantly changes your flight itinerary, you’re eligible for a full cash refund.Rather than give you a refund, airlines would rather just move you to a different flight, which makes schedule changes a valuable opportunity to improve your flight.

Say you originally bought a 6am nonstop flight because it was cheapest. If the airline decided to make that a one-stop flight, you could switch to a more convenient time—without having to pay more. If you had a connecting flight and the airline changes the time, you could see about switching to a nonstop. And if it’s a trip you no longer want to take, schedule changes let you get a full cash refund.

>> Read more about how to use this loophole to change or cancel your flight

17. Join Scott's Cheap Flights

sample cheap flight deals from Scott's Cheap Flights

Yes, it's a shameless plug, but helping people book cheap flights and travel more is what we're all about. We send our members deals like $202 roundtrip to Japan, $164 to Hawaii, and $23 to Puerto Rico—all on direct or one-stop flights on airlines you know. You can even join for free to try us out.

Now that you know the basics, here are some answers to frequently asked questions about finding and booking cheap flights.

I have specific dates/destination. How can I track fares for that?

Both Google Flights and Kayak let you track a specific trip and get alerted when the price drops.

What are really good roundtrip fares from the United States or Canada?

  • Africa: $800 or below roundtrip
  • Asia: $500 or below roundtrip
  • Australia: $800 or below roundtrip
  • Caribbean: $300 or below roundtrip
  • Central America: $300 or below roundtrip
  • Europe: $500 or below roundtrip
  • Hawaii: $400 or below roundtrip
  • South America: $600 or below roundtrip

>> See some of the best cheap flight deals we found in 2020 or read our guides to finding cheap flights to Europe or scoring the best deals to Hawaii.

I found a cheap flight that departs from City A, connects through City B, and arrives in City C. If I live in City B, can I just skip the A-B leg?

No. Once you miss a leg of an itinerary, you're considered a no-show and the rest of your itinerary automatically gets cancelled out.

The only way skipping a leg can work is (a) if you buy two separate one-way tickets rather than a roundtrip, or (b) if you just skip the very last leg of a roundtrip itinerary, in this case from City B to City C. This is a practice called “hidden city ticketing,” which the airlines don’t like (so don’t advertise your plans!) but has a seal of approval from the New York Times Ethicist.

I want to visit multiple cities. What's the best way to book? 

Say you live in NYC and want to visit both Ireland and Spain. You could book a one-way flight from NYC to Dublin and then another one-way flight from Madrid to NYC, but in most cases, that'll cost you more than booking a roundtrip. So, what to do? 

One option is booking an open jaw flight. An open jaw flight is ticketed as a roundtrip but arrives in one city and then departs from another. In between, you could book a cheap regional flight on a separate ticket to get from Dublin to Madrid. The main benefit of an open jaw is that it saves you time; there's no backtracking from your second destination back to your first to catch your flight home.

Another option is a long layover. If you know you want to visit Paris and other city, you could look for flights that have layovers of 9+ hours in another city like London, Reykjavik, Zurich, Munich, or Amsterdam on the way to Paris.

If you want more than a day in the layover city, you can book two separate tickets (we call this the Greek Islands trick) and book one roundtrip from NYC to your layover city and then another roundtrip from that city to your final destination. Unlike an open jaw, this method may require backtracking to your first destination but it can also save you a significant amount of money.

What are the best budget airlines to fly, and which ones should I avoid? 

Budget airlines have proliferated in recent years, giving passengers more choice when it comes to cheap flights. Of course, not all budget airlines are equal. Our favorites, like AirAsia X and LEVEL, offer comfortable seats, reliable service, and reasonable fees.

>> Read our guide to the best and worst budget airlines to fly from the US

Should I clear my cookies before searching?

No. It doesn’t make a shred of difference.

Many people incorrectly assume that the airlines are manipulating prices based on past flight searches. The thinking goes that if the airlines see that a user is interested in a certain flight or route, they’ll raise the prices.

But if this was true, the Flight Experts at Scott’s Cheap Flights would have a much harder time finding deals. We run thousands of searches every day, day after day. If prices were rising based on those previous searches, we’d see it.

Airline and OTA (aka online travel agency) websites do typically access your IP address, but they do that in order to provide accurate location-related information like language and currency—not to manipulate prices based on your activity.

Airline prices are highly volatile. If the price happens to change between searches, there could be a number of factors at play. First, prices fluctuate all the time, and it’s possible that the price simply increased in the few minutes between searches. Second, a price is usually only good for a certain number of seats. Once those seats are sold, the price rises to the next bracket.

If you’re searching on an OTA, it’s also possible that the first price you saw had already expired but the OTA hadn’t yet updated its prices. When you ran the second search, the prices had updated and the new price was higher.

In the wise words of Alexis Rose, “People aren't thinking about you the way you’re thinking about you.” While airline and OTA sites are tracking things like your location, they aren’t obsessively tracking your searches to sneakily increase the prices on flights they know you’re interested in.

When a price increases the second time you search, it’s coincidence caused by a number of factors, or simply a lagging price update. It’s not an intentional move to get more money from you.

While there’s no harm in clearing your cookies or searching for a flight in your browser’s incognito mode, it’s just a waste of time. It’s not going to help you get a better price.

Should I try to get a standby fare? Or book unsold seats at the last minute?

Basically, no. Last-minute deals can pop up, but it’s increasingly rare. In the last week or so before a flight, the price tends to skyrocket.

This wasn’t true 20 years ago as airlines slashed prices to fill unsold seats, but nowadays airlines jack up prices on unsold seats knowing that business travelers are far more flexible on price but can’t make plans until the last minute.

How do I find cheap one-way tickets?

For most carriers, one-way flights are significantly more than half the cost of a roundtrip flight.

If you want to fly into a different airport than you will depart from, it's usually better to book an open-jaw flight (flying A to B, then C to A) on one itinerary rather than two separate one-ways.

Airlines whose one-way flights are around half of a roundtrip include jetBlue, Norwegian, Condor, and basically all intra-continental budget carriers like Ryanair and Air Asia.

>> Read more about how to find cheap one-way tickets

How do I find cheap last-minute flights?

Pray.

In all seriousness, it’s pretty rare to find cheap last-minute flights because airlines typically jack up the price to gouge business travelers who are last-minute planners and not very price-sensitive.  

Cheap last-minute flights are more likely on international routes than domestic routes because business travelers don’t fly international routes nearly as much. In general, using the tips above is the best strategy for finding cheap last-minute flights, but if you absolutely have to fly last minute and want to do so for as little as possible, check out our guide to finding cheap last minute flights for a few additional tips.

Should I fly basic economy to save money? 

If your plans are set in stone and you're not too picky about your seat, a basic economy ticket may be a great way to save money. However, if you prefer the flexibility of changeable (and upgrade-able) ticket and want to select your seat at booking, it may make sense for you to upgrade to main economy. Google Flights and other search sites make it easy to see what you're getting—and any extra fees—and switch classes depending on what's best for you. You can read more about basic economy in our Ultimate Guide to Basic Economy or check out our tips for making a basic economy flight a little more pleasant.

>> Don't miss a great flight deal. Join Scott's Cheap Flights to get cheap fare alerts directly to your inbox.

Last Updated 
June 8, 2021
How to Find Cheap Flights in 2021: The Ultimate Guide
Scott Keyes
Founder & Chief Flight Expert

Scott has traveled to 46 countries (and 46 states!), living in California, to Oaxaca, to Oregon. He’s left-handed, drinks five cups of tea daily, and holds a vendetta against the “Happy Birthday” song. On a dare, he once ate 13 hot dogs (and a bowl of Dippin’ Dots) at the ballpark. He grew up in Ohio and founded Scott’s Cheap Flights in a Denver coffee shop. Favorite airport: PDX.

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