Okay so this started because someone on Reddit told me that if you search for flights in incognito mode, the prices are lower.
I tested it. 47 searches across 12 routes over 3 days. Incognito vs. Normal browsing.
The result? Identical prices. Every single time.
Which got me thinking: how much of the "how to find cheap flights" advice floating around the internet is actually real, and how much is just stuff that sounds clever being repeated by people who never tested it?
Turns out the answer is "a disturbing amount of it is nonsense." But also, some of it genuinely works. And the stuff that works REALLY works. We're talking hundreds of dollars in savings on a single booking.
So I did what I always do when something nags at me. I went deep. Three weeks, probably 200+ hours of research, testing, and cross-referencing. My partner walked in at one point and I had Google Flights open on my laptop, Skyscanner on my tablet, and ITA Matrix on my phone, and I was cross-referencing prices in a spreadsheet.
"Are you okay?" they asked.
I was not okay. I was in the zone. Different thing.
Here's everything I found, organized by whether it actually works.
TIER 1: This genuinely saves money every time
Use Google Flights' flexible date feature
This is the single most effective tool for finding cheap flights and I am mildly obsessed with how underused it is. Here's what you do:
Go to Google Flights. Enter your departure and destination. Instead of picking specific dates, click the date field and select "Flexible dates." Now look at the calendar. Green highlights show the cheapest days. The price difference between the cheapest day and the most expensive day on the SAME route is typically $80 to $250.
That's it. That's the whole tip. Be flexible on dates by even 2-3 days and you can save hundreds.
I tested this on 20 different routes. Average savings from choosing the cheapest highlighted day versus a random day: $127 domestic, $213 international.
Why it works: airlines price each departure date independently based on demand. A Tuesday departure might be in a low-demand fare class while a Friday departure on the same route is in a high-demand class. Same seats, same plane, wildly different prices based purely on which day you choose.
Set price alerts on your top 3-5 routes
Google Flights lets you track specific routes and get emailed when prices drop. EarlyBird Air monitors more aggressively across more routes, but the Google version is free and effective for specific trips you're planning.
The key insight: prices fluctuate constantly. A route might be $450 today, $380 on Thursday, and $520 next Monday. If you search once and book immediately, you're probably not getting the best price. If you track for 2-3 weeks before your flexible travel window, you'll almost certainly catch a dip.
I tracked 8 routes for a month. Every single one had at least one day where the price was 15%+ below the average. Five of the eight had a day that was 25%+ below average.
Book domestic flights 1-3 months out, international 2-5 months out
This is the boring advice that actually works. The "sweet spot" for booking timing exists, and it's roughly:
Domestic US flights: 1-3 months before departure. Earlier than 3 months, the airline hasn't opened their cheap fare classes yet. Later than 3 weeks, the cheap classes are sold out.
International flights: 2-5 months before departure. The sweet spot is wider because international inventory management is more complex.
I looked at fare data across 30 routes over 12 months. The cheapest prices consistently appeared in these windows. Not always. But consistently enough that "book 6 weeks out for domestic" is genuinely good advice.
TIER 2: This works but requires effort
The hidden city trick (buyer beware)
Hidden city ticketing means booking a flight with a connection, but getting off at the connection city instead of continuing to the final destination.
Example: a direct flight from New York to Dallas might cost $350. But a flight from New York to Austin connecting through Dallas might cost $220. If Dallas is actually your destination, you book the Austin ticket and just... leave the airport at your connection.
Does it work? Yes, the savings are real. I found viable hidden city options on about 30% of routes I checked. Average savings when available: $80 to $180.
The catches (and they're significant): - Only works with one-way tickets or the last leg of your itinerary - You cannot check bags (they'll go to the final destination) - Airlines actively hate this and will cancel your return flight if they catch it - If your connection is changed or cancelled, you have no recourse - Doing it repeatedly on the same airline can get your frequent flyer account shut down
My verdict: useful to know about. Risky to rely on. I'd use it for a one-time one-way trip where the savings are $150+ and I'm not checking bags. Not as a regular strategy.
Mistake fares and error fares
These are real. Airlines occasionally publish fares that are clearly errors. Business class to Europe for $300. First class to Asia for $800. These appear because someone types the wrong number into a revenue management system, and the booking engine publishes it before anyone notices.
How to catch them: this is literally what deal alert services exist for. By the time you see a mistake fare on social media, it's usually dead. Services like EarlyBird Air that monitor fares in real-time catch these within minutes.
Do airlines honor them? Sometimes. US DOT rules previously required airlines to honor published fares, but that's been revised. Now airlines CAN cancel mistake fares, but many choose to honor them for PR reasons. My tracking shows about 60-70% of genuine mistake fares get honored in 2026.
The nearby airport trick
If you live near multiple airports, always search from all of them. Price differences between airports 50-100 miles apart can be staggering.
I ran a test: same destination (Paris), same dates, five departure airports within 100 miles of each other in the NYC area (JFK, EWR, LGA, PHL, BDL).
Price range: $412 (EWR) to $687 (LGA). Same destination. Same week. $275 difference based purely on which airport you drive to.
Always check your surrounding airports. A 45-minute drive to a different airport is worth $200+ in savings.
TIER 3: Marginal but real
Tuesday/Wednesday departures
The "fly on Tuesday" advice is old but still holds. Not because airlines secretly discount on Tuesdays (they don't), but because business travelers fly Monday and Friday, which keeps demand (and prices) higher on those days.
My testing: Tuesday and Wednesday departures averaged 12-18% cheaper than Friday and Sunday departures on the same routes. Not life-changing, but $40-80 in savings on most routes.
One-way vs roundtrip pricing
In the US, two one-way tickets now cost the same as a roundtrip on most airlines. Sometimes less. Always check both.
Internationally, roundtrip is still usually cheaper. But not always. Check both.
This saved me $89 on my last domestic booking by mixing airlines (cheapest outbound on one carrier, cheapest return on another).
Positioning flights
If you live in an expensive departure city but have a cheap alternative within driving or short flight distance, consider "positioning" to the cheaper airport.
Example: flights from your home airport to London cost $700. But a $60 positioning flight to a nearby hub drops the London fare to $380. Total: $440. Savings: $260.
This requires flexibility and adds complexity. But for international trips where the fare difference is $200+, the math almost always works.
TIER 4: Myths that refuse to die
Incognito mode gets cheaper prices.
No. I tested this extensively. Airline pricing is not based on your browser cookies. It's based on fare class availability which changes based on demand across all searchers. Not just you personally.
Book on Tuesday at 1am for the cheapest prices.
No. There is no universal "cheapest time to book." Airlines update pricing continuously based on algorithms, not on a weekly schedule.
Use a VPN and search from a different country.
Mostly no. For major US airlines, the departure country determines the pricing. Searching from a different IP address doesn't meaningfully change fares in most cases. Occasionally works for international carriers but the savings are marginal ($10-30) and the hassle isn't worth it.
Clear your cookies between searches.
Same myth as incognito mode, just phrased differently. Airlines don't raise prices on you specifically based on repeated searches. They raise prices when fare classes sell out, which happens across ALL searchers.
The Bottom Line
Here's what actually matters, sorted by impact:
1. Be flexible on dates (saves $100-250) 2. Track prices for 2-3 weeks before booking (saves $50-200) 3. Check multiple nearby airports (saves $50-275) 4. Book in the sweet spot timing window (saves $50-150) 5. Consider one-way mixing or positioning flights (saves $50-200) 6. Sign up for deal alerts to catch error fares and sales (saves $100-500 when they hit)
Everything else is noise. The biggest savings come from flexibility and patience, not from secret tricks or browser hacks.
If you want someone else to do the monitoring for you (which, honestly, same), check how our deal alerts work. We watch fares across hundreds of routes and send alerts when prices drop significantly. It's the hands-off version of everything in Tier 1 and 2.
For more booking strategies, browse our Booking Tips section. And if you already know where you want to go, check our current deals to see what's available right now.