"Clear Your Cookies and Flights Get Cheaper" — I Went All the Way Down This Rabbit Hole

"Clear your cookies and search again. That's how you get a lower price."

A friend told me this, and I figured I'd actually check it. When I started searching around, this kind of advice was everywhere. Use incognito mode, clear your cookies, search from a different device. But is any of it actually doing anything, or are we all just copying each other? I went all the way down to find out.

Spoiler up front: it's half true and half not. Yes, prices do go up sometimes — but cookies are basically not the reason. The real cause is somewhere else entirely, and once you know it, you'll save more money than you ever would by clearing cookies. Stick with me to the end.

Honestly, I believed it at first too

When everyone says it, you kind of just believe it. I was that person — only ever booked flights in incognito mode. Some flight search platforms even write in their own guides that "clearing cookies might help." The logic goes: cookies track your behavior, the site sees that you're serious about buying, and pushes the price up.

When you put it that way, it sounds completely plausible, right? "Of course it's the cookies."

But when I dug into the actual sources, the airline side told a totally different story. Skyscanner has stated officially that they do not raise or adjust prices based on cookies, location, or search history. A Korean airline rep also told Sisaweek in an interview that "there's no scenario where search records cause a price increase." To be honest, even at this point, I still kind of half-believed incognito mode was cheaper.

Here's the part that flipped me. There's an actual experiment that was run — same flight, same conditions, searched twice forty minutes apart, cookies left untouched the entire time. And in some cases, the price actually dropped. Without clearing anything. So the idea that "more searches = higher price" is just demonstrably wrong.

So what actually moves flight prices?

The industry name for it is Revenue Management. Airlines recalculate prices every day, every hour, sometimes multiple times an hour. It's not your cookies — it's a whole system with several inputs.

The biggest input is seats remaining. Flight prices are split into fare classes, with different prices for each tier of seat. When the cheapest tier sells out, the system automatically opens up the next-cheaper tier, which costs more. So if a seat was 320,000 won yesterday and 380,000 won today, it's not because of cookies. It's because someone else bought that last cheap-tier seat between your two searches.

Time until departure is also huge. There are pricing recalibrations roughly at the 6-month mark, the 3-month mark, the 1-month mark. Right before departure, prices climb because there are fewer seats left. But also — and this surprised me — searching too early can mean only the full fare class is open, which is also expensive.

The time of day you search can affect things too. Same flight, same date, but the price in the early morning differs from the price in the evening. That's because airlines re-run demand forecasts at different times of day.

Competitor prices also factor in. If Airline A drops the price on a route, Airline B usually follows.

So it's these four — not cookies — that actually move the price.

One personal thing: when I'm booking for two or more people, I always search with the full headcount selected (like "2 adults" instead of just "1 adult"). It seems to give a slightly cheaper per-person price for me. I'm not 100% sure why, but the price visibly drops. This is purely my personal observation.

So why do people feel like prices go up with every search?

It's cognitive bias. Think about when you search for flights — usually right after deciding to take a trip. So for the next few days or weeks, prices are naturally moving up and down. But because you weren't watching prices before, every new check feels like "I searched again and the price went up." The price was probably moving the whole time. You just weren't looking.

The other thing is that sometimes a seat genuinely gets bought between your two searches. That's the seats-remaining mechanism kicking in. You feel like "I searched five minutes later and the price jumped," but in that five-minute window, someone else grabbed the last cheap seat. It's not the cookie. It's the market — other people are searching at the same time you are.

Now, to be fair, OTA sites (Trip.com, Expedia, those kinds of booking aggregators) — there does seem to be something going on with cache and session-based pricing where the same query shows different numbers depending on your browser state. The industry doesn't officially admit this, but it happens enough that incognito mode "feels" like it works. That said, it's not the airline raising prices. It's the booking platform showing you a cached price or a session-dependent result.

That's why my own habit is: compare prices on OTAs and Naver Flights first, then actually book directly on the airline's official site. I haven't booked a huge number of flights, but every international trip I've taken, I've done it this way.

So is incognito mode useless?

It's actually useful. Just for a different reason than people think.

What incognito mode actually does is: it ignores the cached version of the previous search and pulls in the live data fresh. When yesterday's price seems to be "still there" on your screen today, opening it in incognito grabs the actual current price. That's why prices look different sometimes.

So incognito mode is not "removing the cookie-inflated price." It's "double-checking the price as it is at this exact moment." Knowing this versus not knowing it changes how you use the tool entirely.

One more tip — you don't even need incognito mode for this. On the same page, hitting Ctrl+Shift+R (or Cmd+Shift+R on Mac) does a hard refresh that ignores the cache. For tracking live price movement, this is the fastest way.

So how do you actually get cheap flights?

This is the core takeaway. Way more effective than clearing cookies:

Set up price alerts. Almost every flight search platform lets you set alerts for specific routes and dates. They'll email or push you when the price moves. This is more effective than searching daily, and as a bonus, it gets you out of the "searches make it more expensive" anxiety loop.

Pay attention to weekday/time. Tuesdays and Wednesdays are often cited as the cheaper days, statistically speaking. It varies by route, but it's a real pattern. And within a single day, early-morning searches sometimes show different prices than evening ones. I personally search in the early morning hours most of the time.

Search nearby airports too. It's a more situational tip, but for Tokyo, don't just look at Narita — check Haneda too. For London, look at Gatwick and Stansted, not just Heathrow. Same city, different airport, the price difference can easily exceed 100,000 won. I once flew into a "secondary" Tokyo airport and saved money and the airport was way less crowded.

Consider a stopover if you can. Connecting flights are often cheaper than nonstops. If the layover is 8+ hours, you can even sneak in a quick sightseeing trip in the connection city. Just confirm whether you need a transit visa first. This one is really only worth it if you have time to spare.

So, the real conclusion

"Searching the same flight twice raises the price" is a widespread, unverified urban myth. There are some OTA-side cache effects that might cause similar appearances, but airlines tracking you to raise your specific price is not something that actually happens at any meaningful scale. If it were proven they did, the backlash would be enormous.

So instead of spending time on incognito mode, set up the price alert (yes, it's annoying), work backward from your travel date to find your booking window, and don't forget to check nearby airports and stopovers. Those things actually work. How you search matters way less than when you decide to buy.

Flights are kind of like hotels — there are more variables to consider than people realize. I really hope this post helps you grab a cheaper ticket on your next trip.