⚡ Key takeaways
- Incognito does not lower the fare. In a side-by-side test, the cookie-free browser was more often the more expensive one.
- Fares move all day for everyone, so a higher price on your second search is normal.
- What does help: the days you fly, accepting a connection, and booking early enough.
You search a route, come back an hour later and the fare is higher. The usual tip is an incognito flight search: open a private window so the airline can’t see you coming back. The short answer is that it doesn’t work. The fare went up because airline prices move all day, for everyone. Below is what the tests found, and the three choices that actually save money.
Does incognito flight search get you cheaper fares?
No: when browsers disagreed in a side-by-side test, the clean browser was more often the expensive one.
In 2016, Consumer Reports ran 372 searches on nine booking sites, each time in two browsers at once: one with cookies and one wiped clean. In 42 pairs the price differed. The cookie-free browser showed the higher fare 25 times and the lower fare 17 times.
Why the fare changed when you searched again
Airline prices move constantly, so a second search often shows a different number. In the same Consumer Reports test, one route differed by up to $238 from one day to the next.
The Dutch consumer regulator ACM studied more than 14 million ticket sales on 56 routes between July 2022 and July 2025. Its summary, dated September 29, 2026, says the base price of a ticket is set dynamically, so it keeps changing. On average, buyers paid 30 to 35 different prices for the same base ticket while it was on sale.
Do airlines set prices by who you are?
Rarely, according to the research and the regulator that checked. Researchers who studied a large U.S. airline’s internal pricing data wrote in their paper that “Fares are not personalized”. ACM found personal pricing “used to a very limited extent”, mostly loyalty programs and incidental discounts such as birthday offers. It does expect airlines to experiment with it more.
What does lower the fare
Your travel days, a connection and your booking window matter far more than your browser. Table 1 shows what Google found in five years of Google Flights data for U.S. departures, published October 5, 2026. These are averages, not guarantees.
| Choice | What Google’s data shows |
|---|---|
| 1. Days you fly | Out on Monday, back on Tuesday or Wednesday: about 14% cheaper than weekend flights |
| 2. Nonstop or connecting | Nonstop tickets cost about 20% more on average |
| 3. Booking window | Domestic: lowest average price about 39 days before departure (low range 22 to 57 days). International: book as soon as you can, because waiting saves little |
What to do before you book
A private window is fine for privacy. Just don’t expect it to change the price. Spend the effort here instead:
- Move your dates. Check a Monday departure and a Tuesday or Wednesday return.
- Look at connections. Compare the nonstop price with the cheapest one-stop option.
- Book in the window. For a domestic trip, aim for about 39 days, roughly five to six weeks, before you fly.
Before you pay, read the fare type: the cheapest ticket often has the strictest rules on changes and bags.
Frequently asked questions
Does a VPN get you cheaper flights?
None of the tests above looked at VPNs, so there is no evidence it helps. The FTC reported in January 2025 that location and browser history can be used to target individual shoppers, but that study covered the pricing firms retailers hire, not airlines.
What is the cheapest day to book a flight?
In Google’s data, booking on a Wednesday saved only about 1.4% compared with Sunday. The days you fly make a much bigger difference.
Booking a hotel too? Our guide to Agoda hidden fees at check-in covers the surprise costs there.
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