Of all the myths surrounding travel and finding cheap flights, one stands out. We hear it again and again and again, from beginners to even so-called travel experts and social media influencers. You've probably heard it too it's practically common knowledge.

The Claim: Use Incognito Flight Searches To Find Lower Prices You should search incognito for flights or clear the cookies on your internet browser because the website is tracking what you're looking for and will jack up the price.

The Reality: Incognito Mode Will Not Help Let us say this unequivocally: Searching for flights incognito does nothing. Absolutely nothing. Nor does clearing your cookies.And we areexperts at airfare and finding cheap flights.

At Thrifty Traveler, we find flight deals for a living and send them toThrifty Traveler Premium members. We're searching all day, every day for flights. If airlines were tracking our searches, we'd never find cheap flights. And trust me, we do.

Pssst that thing you've heard about booking on Tuesdays is wrong, too there's no best day to book flights, either!

It sounds like it makes sense, right? The idea that you're being tracked is an easy explanation for why the price of a flight you were looking at changed an hour later when you went to go book. Searching flights incognito makes travelers feel like they've got the power like they're beating the airlines.

But it's just not true. Airlines are not tracking your searches. Neither is Google Flights the best search platform for finding good deals on airfare or most other search engines and online travel agencies (OTAs) like Expedia, Hopper and Priceline.There is no evidence that sites are raising flight prices the more that you search for a specific trip, or by a previous search.

So what's the answer behind the constantly changing flight prices, then? Why did that ticket you were looking at suddenly jump in price?

Explaining Changes in Airfare The reality is that airfare pricing is fickle, and it's always changing. Airlines are constantly altering their prices as tickets sell and demand changes.

One simple explanation behind a sudden change in price is something called the airfare's fare class. While you just see economy and first class when you walk on the plane, airlines sell an alphabet soup's worth of tickets called fare classes and it’s literally an alphabet, as most airlines have a fare class for every letter.

Here's a look at just some of United Airlines' fare classes, for example.

There are close to two dozen or more different fare classes for even a standard economy seat, each with its own set of rules for upgrades, earning miles, and more. Basic economy fares– the bare-bones tickets sans seat assignments or checked baggage – are represented by an entirely different fare class. Even award fares booked with miles have a distinct classification.

Here's the important part: Every fare class has its own price. So when the cheapest fare class sells out or an airline simply decides to remove that fare class the price will jump up to the next, higher-priced class.

So let's say you're looking at roundtrip flights from Minneapolis-St. Paul (MSP) to Las Vegas (LAS) on Google Flights and you see a good deal for $158 roundtrip. Little do you know, there's only one ticket remaining at that lowest price.

So when you go back an hour or even just a few minutes later and find that price is gone, it's not because Delta is tracking your searches. That cheapest ticket likely just sold. Or Delta decided to pull it.

That's it. These quirks with airfare classes and pricing explain 90% or more of the frustrating fluctuations you may see.

In some cases, you might be searching through Google Flights and click through to book a good deal only to find the price has shot up. But again, it's not that you're being tracked. Instead, because flight prices are changing constantly, sometimes Google Flights will briefly display an out-of-date price that has since changed due to cached data.

Those mismatches typically get fixed within minutes, if not seconds. But every once in a while, it may look like Google Flights or your airline have tried to pull a fast one on you.

What About Using a VPN to Find Cheaper Flights? Right after searching incognito and clearing your cookies, using a VPN (virtual private network) to disguise the location you're searching from might just be the most frequently repeated travel tip for finding cheap flights. In this case, it can sometimes work but not for the reasons you may think.

It's not about how you're searching: It's about where you're searching from. Some flight search platforms and even individual airlines can charge drastically different amounts based upon the point-of-sale or at least where the website thinks you're buying a ticket.

Whether you use a VPN or simply navigate through an airline's website to select a different location, it can result in some savings or additional costs. For example, when I needed to book flights from Bogota (BOG) and Cartagena (CTG) and back a few years back, searching from the U.S. yielded roundtrip fares for just over $111.

But after switching my location on Avianca's site to Colombia itself, itpulled up the exact same flights at 354,000 Colombian pesos dropping the price by $30 apiece to $81 USD.

If you're trying this money-saving method, make sure you've got a credit card that doesn't charge foreign transaction fees!

But don't assume that searching from the home country (and paying in its currency) is always the key to savings. For example, these long-haul flights from New York City (JFK) down to Buenos Aires (EZE) on Aeromexico clock in just over $1,000.

By switching my point of sale to Argentina itself, the exact same flights cost 229,637 Argentine pesos. That works out to more than $1,719 USD an extra $700!

Let me be clear: This is incredibly hit or miss. You could run 100 searches around the globe and only run into this issue once or twice. It just depends on where you're flying and where you're buying.

Is it worth trying? Yes, especially if you don't like the prices you see on a flight abroad, change your point of sale or fire up a VPN and compare the prices.

But though this technique can help at times, it's by no means a silver bullet to saving on flights.

Bottom Line If you really want to know how to find cheap flights, you need to know the facts.

You can search incognito for flights if you want, but it's not doing you any good. And stop wasting your time clearing your cookies, too. These tips have been passed around for years even by so-called experts. But they're simply not true.