Everyone knows that you need to book flights in advance to avoid spending a fortune on airfare but most don't know how complicated the airfare ticket pricing really is. Airlines typically offer more than a dozen price points for the same seat on the same aircraft - prices and rules that can and do change frequently throughout the day. Simultaneously automated inventory systems decide at any given moment which price point to offer a shopper, based on dozens of factors including current and historical bookings. This can get really complex but I'd like to break down as much as I can what I've discovered from my travels and research. Let's start with the three keys to buying inexpensive plane tickets:
Shop multiple airlines
Time your search right
Be flexible with your itinerary
Dynamic Pricing & Perishable inventory
Before we talk about shopping airfare you should understand some of the drivers for why the system works the way that it does. An airline's goal is to sell every single seat in the plane at the highest price that passengers will possibly pay. When the aircraft departs, the unsold seats cannot generate any revenue. Those unsold seats can be said to have perished. Airline tickets are some of the most perishable inventory in the world and are subject to the most volatile fluctuations in price. Airlines use various inventory controls, for example, they can offer discounts on low-demand flights where the flight probably won't sell all of the seats. When there is excess demand, the seats can be sold at a higher price. The price of each seat varies directly with the number of seats reserved, that is, the fewer seats that are reserved for a particular category, the lower the price of each seat.
Simple enough right?
This sort of variable pricing strategy is called yield management and it is based on understanding, anticipating and influencing consumer behavior in order to maximize revenue or profits from a fixed, time-limited resource.
Tracking cookies and user history and browser information can all factor into the different prices that are served up when you search for a flight. When you can, begin your search anonymously, remain signed-out until you begin to purchase your fare, use incognito mode to avoid cookies and retargeting. (Obviously if you are logged into an account this method will not work) Be aware that Incognito mode does not hide your IP address which means that your location, your browser, operating system as well as your own address is not hidden by using Google chrome in this mode. This can play a factor into pricing from certain outlets as well. Orbitz was found to serve up higher priced options to visitors using a mac.
Barney Harford, the company's CEO, was a guest on USA Today's Hotel Check-in blog and wrote this:
"We've identified that Mac users are 40% more likely to book a four- or five-star hotel than PC users. A similar skew applies for iPad users. We can use that information to influence which hotels we recommend to users we see searching on a Mac or an iPad versus a PC for example. On our website, once you get to the page for a particular property (let's call it "Hotel A") we show consumers a list of alternative hotel recommendations. This list is primarily made up of nearby properties that were ultimately booked by customers who had also viewed Hotel A. That's a pretty useful feature already, but we're then able to personalize that list by taking into account factors such as whether we see that the user is using a Mac or a PC."
This is far outside of the scope of this article, but almost all businesses use social media “pixels” (essentially a snippet of code) to uniquely identify users and track interactions across the web. Think of this like a server-side tracking cookie that you are opted-into once you’ve signed into Facebook. This is why it might feel like Facebook or Instagram are listening through your phone microphone.
Shop Multiple Airlines
No single airline always has the best fares every single time. If you're not shopping multiple airlines you're likely throwing away hundreds of dollars every time you buy a plane ticket. Being blindly loyal to an airline or the alliance that it belongs to is really only worth it if you fly enough to earn a status level in the frequent flyer program to get things that you would otherwise spend money on. Usually this is in the case of a business traveler who gets reimbursed for their airfare. For the sake of this guide, let's consider that out of scope. It gets into credit card and loyalty points hacking which is more the specialty of the points guy.
I usually won't spend a significant amount more just to travel on an airline and collect the points. Price and schedule are always important consideration so I don't necessarily pick the least expensive ticket either. You might get lounge access, expedited security screening, extra baggage allowance, priority boarding, and free upgrades when your class-of-travel is full. How much that is worth to you is something only you can decide.
There are a few airlines that offer rock-bottom pricing at the cost of significant comfort or with tons of hidden fees to make up the difference. Do some research when flying an airline where the price seems too good to be true. You probably already know some of these from the horror stories, Spirit, Frontier, Southwest, Allegiant, WOW. You may have even seen news articles with headlines like "$55 Tickets to Europe" or "WOW: $69 one-way fares to Europe now on sale". Unfortunately they are clickbait headlines (shame on you CNBC and CNT) because they neglect to mention the larger return flight cost, and the hidden fees involved in everything.
I had the opportunity to try out WOW airlines in 2016 when I was traveling to Iceland. I had a mostly positive experience but It could easily go either way. The baggage rules seem normal at first glance:
Each guest is permitted 2 items in the cabin. 1 personal item (free) and 1 carry-on bag (paid).
But then you look closer and you see the dimensions are different than other airlines and you need to pay for a carry-on bag. The personal item is about the size of a medium-large camera bag or three laptops stacked on top of one another. I tend to roll deep with luggage, lots of photo equipment in tow so I'd have to buy a carry-on and checked bags (I did purchase these in advance when I flew WOW air).
Included in the WOW airfare is one small personal item up to a maximum of 42x32x25cm/ 17x13x10in (10kg/22 lbs), such as a small bag/backpack, laptop or a camera bag. Must fit under the seat in front of you.
WOW air guests can purchase allowance for one carry-on bag, up to a maximum of 56x45x25cm/ 22x18x10in, including handles and wheels and no more than 12 kg/26 lbs. According to standard price list.
Taking a look at the 'standard price list' you will see that fees and additional charges vary by airport location, flight dates, and whether the fee is paid in advance, or the day-of the flight. The entire list of fees is so enormous I won't include a screenshot but have a look at it here. Some of the fees are absolutely insane. Booking through the call center is a $27.99 fee per leg of the journey. If you book online but then realize you forgot to add the luggage fees online it's a $17.99 fee to pay the fee by phone PER LEG OF THE JOURNEY. If you spell your name wrong that's a $17.09 fee. Need to change your flight? It's $90.99 plus the difference in fare if the new fare is more expensive. If you want to carry on a bag it's $49.99 at the time of booking, if you decide later it's $69.99 at check-in and $99.99 at the gate. Same thing for a checked bag, $69.99, $79.99 and $99.00 respectively. Overweight fees are $19.99 PER KILO. Legroom starts at $10.99 and goes up to $299. I think you get the point I'm trying to make here. Read the fine print and don't jump to book when you see misleading headlines before you've done some thorough research.
I had a great experience with WOW flying SFO → REK, I had already read the fine print and had all of my details squared away. I brought my own snacks and water. The staff was great and the flight was enjoyable. Flying from DUB → REK was not as pleasant, but that's a story for another time. Bottom-line: Do your research. Square away everything away in advance before flying one of these ultra-low-fare carriers.
The best way to shop multiple airlines is with a travel site that aggregates airline ticket sales so you can compare rates easily with better tools. I will usually try cross-referencing that price with the price I can get directly booking with the airline and find that the airline has a higher price. But it's always worth it to double check especially since Delta and Southwest withhold airfare data from sites like these. These Airlines want to be the only sales outlet for their own flights. By controlling their own inventory, an airline is better able to track their customers and not share their revenue with any outside sales outlets.
My absolute favorite sites (>90% of the time where I book a flight) for booking airfare are:
Other online agencies include: (be sure to read the fine print, some of these agencies offer better deals that cannot be changed once booked or impose heavy fees)
GTFO (this used to be an app but switched to email lists only)
Timing Your Search
There are so many theories about what time of day to buy tickets out there and they change frequently. Most sources will tell you that the best time to book a flight is usually Tuesday at about 3 pm EST. Because any weekend fares that were locked into a higher price are released. Most airlines issue weekly promotions late Monday or early Tuesday and by mid-afternoon, competing airlines have matched the lowest prices. Tuesday afternoon is usually when you’ll have the most deals to choose from. For the most part I've found that as long as you shop on weekdays, especially earlier in the week you'll be better off.
Edit: In 2019 I’ve had the best luck on Monday mornings with the deals tapering off through the middle of the week.
Possibly the most important thing to consider, more important than the day of week or time of day is the date relative to the departure date. Cheapair, an OTA (Online Travel Agency) did an analysis on 1.3 billion airfares from 2015 and published the results of the study. They found that 21 days to 115 days (three and a half months) is the "prime booking window." They identified five different fare classes. First Dibs, Peace of Mind, PBW (prime booking window), Push your Luck, and the Hail Mary.
First Dibs (197 – 335 days out): Most airlines begin selling tickets 335 days before the flight. First Dibbers get their pick of flight times, nonstop options and seats. However, they pay an average of $50 more than they would during the “Prime Booking Window.”
Peace of Mind (113 – 196 days out): The Peace of Mind zone offers a balance between flight options and price. Travelers pay an average of $20 more per ticket than they would in the Prime Booking Window, but also have more flight options to choose from.
Prime Booking Window (21 – 112 day out): This is the zone for bargain hunters. During these 90 days, fares fluctuate a lot, sometimes day to day. Travelers are urged to check for cheap airline tickets frequently during this period and to buy when a bargain pops up.
Push Your Luck (14 – 20 days out): In the period between two and three weeks out, fares can vary dramatically. Depending on how full flights are, travelers may get a fantastic deal, or they may pay significantly more. Popular flights during peak seasons are less likely to have low fares in this zone.
Hail Mary (0 – 13 days out): On rare occasions, the Hail Mary zone offers the best rate. However, 7-13 days out, travelers pay an average of $75 over the Prime Booking Window. 1-6 days in advance, that premium shoots up to $200.
I've found that these fare classes hold very true to their descriptions. For individual trips, the best time to buy varies substantially depending on the destination, time of year, and travel days. But on average, the best possible time to buy a fare without gambling is the 21-112 day prime booking window.
It's also important to note that this analysis was done with United States domestic flights. International flights are an entirely separate complication, with a lot of different variables at play. You can't really do a destination to destination comparison since each are so incredibly different. There is usually a seasonality component in flight prices and you will see a huge disparity between the price during the low tourist season and the high tourist season. There also might be extenuating circumstances that could affect ticket prices, are there political issues? Are the Olympics being hosted in this country? Was there a natural disaster in that area recently? All of these may play a part in what might cause a shift in ticket prices.
Being Flexible With Your Itinerary
If you can be flexible with travel plans, a little inconvenience can save a lot of money. When I travel domestic, it's usually for a long weekend so my dates aren't as flexible as I'd like but it's still possible to find a little wiggle room in there. Searching with flexible dates can reveal a significantly discounted fare that you might not otherwise have found if you can leave a day early or come back a day later than originally intended. Generally larger airport hubs and major cities have cheaper fares, if you can leave/arrive at a major hub the price will be significantly lower. Flights with connections can also save a considerable amount on a fare if you have enough time in your itinerary for a layover. This really comes down to how much waiting you can handle, anything less than an hour in most airports and you will likely miss your connecting flight, anything over 8 hours and you'll be reenacting this video. It might be worth the trouble, sometimes you can get a flight for half-price with a connection. So it depends on whether you want to spend more money or time on the trip.
There is an old adage: "Fly Hungry, Fly Tired" It means that flights around meal times and overnight tend to be significantly cheaper and less crowded because less people are willing to give up those comforts for a cheaper fare. The same is true for any time that most people won't want to be traveling will yield the best fares. The days leading up to Christmas Eve? Prohibitively expensive. Christmas Day? Not nearly as bad. Right after New Years Day? Prohibitively expensive. A few days into the week after and the fares will return to a normal price. These will obviously vary from country to country. Golden week in Japan is the number one travel time for Japanese nationals since it's the most national holidays in a row; Whereas it's a great time to travel in the United States.
Another great service is Scottscheapflights. They routinely find pricing mistakes or large drops in price for certain windows and send these to subscribers via email. There are two tiers of membership, free and paid. The free version is supported by ads, and the paid version swaps the ads for a fee. The paid version has more deals and also has the option to only alert you when deals come up for your home airport.
I was recently shopping for a flight from San Francisco (SFO) to Tokyo (TYO). I'll take you through the process of buying my ticket.
The very first thing that I'll do is open an incognito browser window and navigate to kayak.com and google.com/flights in multiple tabs and plug in my airports and intended travel dates. You'll notice that I use the metro area airport codes because TYO includes both Narita (NRT) and Haneda (HND) airports so I can see which fares are lower.
Google has a few great tools to visualize pricing immediately. The first of which is the calendar pricing tool which shows you the price of your flight based on the date you are selecting, so if your other date is firm, you can select the optimal date if price is your primary driver.
If you prefer to see the price with a grid of flexible departure and arrival dates the flexible dates tool is incredibly helpful. The rows represent return dates and the columns represent departure dates, so it's easy to visualize shifting both dates for the optimal price.
The third tool that Google has for visualizing price is the price graph. The price graph is excellent when you know how many days you intend to stay but don't quite have any dates in mind and want to explore price data. The graph will show the lowest fares for an n day trip and you can pan to see different months or lengths.
Once I have settled on dates or prices it is time to chose flights and book. I have flown this route a few times before so I have prior knowledge that around $1,000 USD is a good deal for this flight round trip. Anything over $1,000 is above market, and anything below $800 USD is an incredible deal. If I didn't know this before booking, I would select the toggle that allows me to track prices (right above fares in the screenshot below). This will allow me to see if the fare rises or falls according to the fare classes identified by cheapair and it helps me get a baseline figure for how much this flight will cost.
Before booking anything I want to cross-reference these fares with another source. Sometimes I'll go direct to an airline I see in the search results or an airline that I have points with, but in this case I'm going to check kayak.
The very first thing to look at is the Our Advice panel in the upper left. Kayak uses their fare data to determine if fares are likely to increase, decrease, or remain the same based on current and past fares. I can see that fares are not likely to decrease anytime soon since I'm within the push your luck fare class. I can see that Kayak has a lower price displayed, but if you look closely at the fare displayed there it's a connecting flight in Beijing (PEK) for 14 hours on the initial flight and 21 hours on the return flight. You can also see that it is $780 directly with Air China, so if you book through Kayak it's $18 cheaper. This all boils down to what matters to you, cost or convenience.
I've done a layover in Shanghai (PVG) and I can say from experience that the savings would need to be greater than $500 and the layover would have to be four and a half hours or greater (but less than 12) to make it worth it in my opinion. This is because of the way that PVG is designed you must enter the country, pass through immigration, collect your luggage, pass through customs and exit the airport with all of your luggage before you can re-enter the airport and pass through check-in, luggage check, security, immigration and customs before you can queue for your connecting flight. Paying an additional $300 to avoid the hassle is absolutely worth it to me.
Some International airports have a international transfer that allows travelers to pass through an expedited customs process to make a connecting flight quickly like Suvarnabhumi (AOT) or Amsterdam Schiphol (AMS). It completely depends on where you chose to connect. You'll need to make this decision based on what is more important to you.
Even while reviewing flights for this article the initial flight I had selected has been removed, it may have been booked by another traveler, or my session data may have betrayed my intent to shop around. Let this be a warning to you (and me).
I was tracking dates on Google flights long before I actually purchased my ticket and you can see the trend line almost exactly mirrors the trends that Cheapair found in their study. At 23 days before there is a $200 (33%) increase in price, and then at 13 to 3 days before it returns to the 33% above PBW price. 2 days before it jumps $97 (12.1%) and day-of it becomes $1,260 (71.2%). I've seen this pay off before on other flights but you really run the risk of the fare doubling so it's a huge gamble in the last 7 days before the flight.
If you don't know where you want to go, but you have dates or even a month in mind that you might want to go somewhere both Kayak and Google Flights have incredible Explore features to help find great deals on airfare when you don't even know what destination you want.
Kayak's tool offers some suggestions based on the map and activity, with sliders to adjust budget and travel time or dates.
While Google Flight's Explore tool both offers a map with price and date filtering, there is also a suggested location with more vague options like "I'd like to go somewhere in July for one week leaving from SFO" and Google will offer up suggestions like London for $980 or New York City for $336. You can also change it up by suggesting a location and Google will suggest the optimal time to go, or interests and it will suggest a location to partake.
Use incognito mode signed out
shop multiple airlines.
Only buy tickets for miles if you don't pay for the tickets or if the price difference isn't too great.
Time your search right, buy your tickets on a weekday, preferably early in the week around afternoon-ish.
Book during the PBW wherever possible.
Be flexible with your itinerary.
Take a layover if you have time to spare and it results in a significant reduction in fare.
Fly hungry; Fly tired.
Try to travel when others won't want to travel or during the tourism off-season.
If you have more money than time take the nonstop and fixed dates.
If you have more time than money search flexible dates and connections.
Know the market rate and snag up a great deal if you find one.
Set up fare alerts and follow low-fare services
Travel the world. Meet new people. Take lots of pictures. Have great experiences. Tell great stories.
Edit 2/24/19 - I’m republishing this with some updated figures and information that has changed since originally publishing.
Full disclosure: I did not receive any special treatment, compensation, or freebies for writing this article. (hit me up United)
 Yield management
 Behavioral Retargeting
 Mac Users Have Money To Spare Says Orbitz
 2017 Global Air Travel Outlook: Expedia and Airlines Reporting Corporation Release Report on Worldwide Air Travel Trends and Pricing
 CheapAir.com Study: The Best Time to Buy Airline Tickets
Have you had any luck with the above? Got a different method? Let me know in the comments below!