AFFILIATE DISCLOSURE: This article contains affiliate links to a few of these search engines, which means I earn a small commission if you book your travel through them.

If there were an Olympic sport for booking cheap flights, I think I’d win a medal.

I’ve flown across oceans for $106, to Latin America for less than the price of a decent dinner, and last-minute domestic flights for under $50.

I don’t have any elite status. I don’t hoard credit card points. I don’t fly business.

Instead, I’ve developed a system. Flight search engines, or aggregators, or whatever you call them, are part of that system.

Over the last six years of living car-free and traveling constantly (often on budget airlines people love to complain about), I’ve used just about every flight search engine out there:

For this article, I show you how I use them and for what specific purpose to find the cheapest flights available.

There Is No “Best” Flight Search Engine

I want to be clear. There is no best flight search engine.

If you pack light, travel flexibly, and don’t need your flight to leave at 10:30am on a Friday, that’s how you snag the cheapest flights.

The right search engine just helps you see all your options.

They all pull from the same airlines and the same inventory.

Google Flights isn’t hiding cheaper seats from Skyscanner. Skyscanner doesn’t have a private stash that Momondo can’t see. If you search the exact same flight, you’ll almost always see the same base price.

So why do some people swear one site is cheaper? Or has the best deals?

What the Differences in Flight Search Engines Are

• How they handle flexible dates. SkyScanner got popular because of this.
• How they handle flexible destinations
• How they handle different route options
• How they the results
• Their transparency with fees (like baggage upgrades)
• The order they show options

In other words: They differ in how they help you think.

If you’re a traveler like me who never checks bags, usually has flexible dates or even airports, then different interfaces will help you see different flights available.

It’s the flexibility where the savings are.

The Best Flight Search Engines for Budget Travelers

I’m a budget traveler. So that’s what I use. I often check multiple, depending on the type of search I’m doing. I will give you real world search examples for my trips to Europe and Japan.

If you’re a budget traveler, you’re likely also a flexible traveler, able to go on a different day or a different season to save several hundred dollars. I was a digital nomad for two years, and I often planned my travel around the cheapest flights I could find.

So this is for you if you…

• Don’t check bags
• Have some level of flexibility, whether that’s the destination itself, the season, or even the day of the week
• You don’t mind budget airlines. I’ve written before about how budget airlines work and how to make them work for you.

Best For Backpackers and Nomads: Kiwi

If you’re the kind of traveler who thinks, “I don’t care exactly where I start, I just want the cheapest way to get there,” you’re going to love Kiwi.

This is not the most famous flight search engine.

It’s the most chaotic, and for flexible travelers, that’s a good thing.

Kiwi is great for backpackers, nomads, and budget travelers, specifically if your search includes leaving from or arriving in multiple airports.

This makes more sense with a real example to show what it can do.

What Kiwi Does Better Than Others

1) Multiple Origin and Destination Searches (At Scale)

Last year I planned a trip to Europe.

I live in New York. But I’m also an easy train ride from Boston. And if it saved me a few hundred dollars, I’d absolutely take the train. I’ve done this before on my way home from Spain to snag a $106 Crossatlantic flight.

On the destination side, I wanted to end up in Spain, but I didn’t care if I flew into Paris, Lisbon, Madrid, or even another city within train distance.

Kiwi let’s you search all these options at once.

You can see I can also select the date range, and it gave me several cheap options from several cities on several days.

You can set multiple departure cities, multiple arrival cities, and flexible date ranges.

It shows you combinations you wouldn’t think to try manually.

That’s how I discovered that the cheapest way to fly to Japan from the East Coast wasn’t from New York or Boston. It was from Montreal. It saved me around $600.

My parents live two hours from Montreal, so it became an excuse to visit them, and cut hundreds off my ticket.

That is a backpacker/nomad type of mindset, but Kiwi helps you consider these options that most others wouldn’t.

Try a search on Kiwi here.

2) It Builds “Unusual” Routes

Other flight search engines do this, but Kiwi often stitches together bookings from different airlines.

That means:

• Separate tickets
• Budget carriers combined with legacy airlines
• Routes traditional search engines won’t surface cleanly

That means if your first flight is delayed, your second airline does not care. This helps you see the options. In practice, I’ll know that it’s cheaper to take two flights on separate airlines and plan a full layover day. (This is also what I’m using on my Japan trip, combining a Montreal –> Vancouver and then Vancouver –> Tokyo route on two different airlines.) I’ve never been to Vancouver, so I’ll get to spend a day there.

How I Use Kiwi (My Exact Process)

That’s why I use Kiwi as a discovery tool, not a booking platform.

I find the route on Kiwi.

Then I rebuild it directly on airline websites or confirm pricing on Google Flights.

Kiwi is for brainstorming.

I’ll look at the flights I found on Kiwi and book them on the airline’s website.

Here’s a clearer checklist.

1. Enter 3–5 departure airports
2. Enter 3–5 possible destinations
3. Search by month
4. Sort by cheapest
5. Take note of promising routes.
6. Rebuild and verify elsewhere (like Google Flights)
7. Book directly with the airline

Kiwi is undoubtedly one of the best tools for seeing options that are hard to find elsewhere.

Yes, it’s chaotic. This is the flight search engine equivalent of a party hostel (IYKYK). I’ve written a longer review of Kiwi here.

Best When You Can Go Anywhere: Momondo

If you know when you want to travel but don’t care where you go, Momondo is the most intuitive inspiration tool I use.

Who It’s For

• Travelers with fixed vacation time
• People who just want “somewhere warm” type of booking.
• Budget travelers who choose destination based on price
• Flexible nomads between locations

If you’re staring at your calendar thinking, “I have one week in October and $500, where can I go?” this is the best starting point.

What Momondo Does Better Than Others: The Map View

I do love Momondo’s map view.

It’s a fast, clean site with less ads and pop-ups.

How I Use Momondo

1. Plug in my departure city
2. Use map view
3. Look around
4. Cross-check promising routes and dates on Google Flights

It’s another brainstorming tool.

Best for Flexible Months: Skyscanner

If you’re flexible by weeks or seasons, Skyscanner is still one of the most powerful tools on the internet.

Who It’s For

• Travelers who can leave “sometime in May”
• Travelers who can travel during the offseason
• Anyone willing to shift departure by a week or two to save $200+

What Skyscanner Does Better

SkyScanner is famous for the “Whole Month” view.

Search your route. Select “Whole Month.”

And it instantly shows the cheapest day, without forcing you to click each individual date. It’s nice. For my Europe trip, Skyscanner’s month view showed me a cheaper departure day than Kiwi did, simply because it made the price patterns more obvious.

Skyscanner can feel cluttered. It will often send you to third-party booking sites.

And like Kiwi, I don’t book through it directly. It’s another discovery tool.

How I Use Skyscanner

1. Search by “Whole Month”
2. Sort by cheapest
3. Identify 2–3 promising departure dates
4. Check those exact dates on Google Flights
5. Book direct

Kiwi and Momondo expand geography, Skyscanner expands time.

Best for Deciding Between Trains, Buses, and Flights: Omio

Most flight search engines only show you flights. Which makes sense. They’re flight search engines.

But sometimes the better question isn’t “which flight,” it’s whether you should take a flight at all.

As far as I know (and let me know if I’m wrong), Omio is the only tool that lets you search flights, trains, and buses side by side in a single search.

For budget travelers like me, that’s great because trains and buses are usually cheaper and better than flying, especially once you factor in baggage fees, airport transit, and time getting to the airport.

They’re also significantly better for the environment. (Jet fuel, it turns out, is really bad for the planet.)

If you’ve ever thought, “I could probably take the train for this,” Omio is the tool that will tell you whether that’s true. It’s a nice tool in the budget traveler’s arsenal.

See how flights compare to trains and buses with Omio.

How I Use Omio

I open Omio early in the planning process, before I’ve decided how I’m getting somewhere. If it’s on the same continent, I’ll usually start with Omio just to see.

Omio is also really useful for Western Europe travel, where there are tons of trains to choose from.

Once I see what the train or bus options look like, I cross-reference the flight side on Google Flights. Then I decide. If the train or bus is reasonable, I’ll almost always do that. (Personally, I love a long train ride.)

Like with flight search engines, I use Omio as a discovery tool and generally book direct with the operator when I can. Booking direct means no service fee, clearer fare options, and one fewer middleman if something changes.

That said, Omio does offer a “Flex” add-on that lets you cancel within two hours of departure. That can be useful if your schedule is uncertain and you want to lock in a price without fully committing.

You can read my full review of Omio here.

Best for Precision and Final Decisions: Google Flights

I think Google Flights is some of Google’s finest work.

Who It’s For

Google flights is an all-arounder. But it’s particularly good for..

• Narrowing in on a route
• Comparing baggage policies
• Tracking price trends

It’s good for just about any search once you have a clear idea of your route and dates.

What Google Flights Does Better

Price History & Tracking

It shows how a price compares to historical comparisons for that route.

If it looks low, I’m likely to book. If it looks high and I’m far out from my trip, maybe I’ll set a reminder or a price alert notification, another sometimes useful Google Flights feature.

Baggage Comparison

Google Flights will show you whether that flight cost includes a full-size carry-on for no extra charge. If you’re someone who never checks bags, you may count on that carry-on.

How I Use Google Flights

1. Confirm routes I discovered elsewhere
2. Check price history
3. Set alerts if I’m waiting
4. Go to airline website and book direct

My Checklist: How I Use All The Best Websites to Find The Best Deal

For me, there is no “best,” one, because they work together or for different purposes.

First, I ask myself what I want out of the trip.

If I have strict origin and destination, but the most flexible dates, I start on SkyScanner.

If I have inflexible dates, but many ideas for trips, I start on Kiwi and see what’s cheap for multiple routes.

After that, I go to Google Flights, look at the date I’m traveling, and make sure I didn’t miss anything that the other aggregators buried.

Then, I almost always book on directly on the airline’s website. These tools are just for finding the deals.

The Type of Site I Avoid: Online Travel Agencies

Sites like Expedia, Priceline, Booking, and other online travel agencies are fine for searching (although inferior to the tools I outline here in my opinion), but I almost never book through them.

When you book directly with the airline, you can control your reservation and deal with the airline if something changes. The middleman confusion is a pain.

The only time they make sense is if you’re redeeming through a credit card portal or some special discount or credit.

I use aggregators to discover. I use airlines to book. I avoid the travel agencies trying to get a cut for doing nothing.

Are AI Flight Tools Worth Using?

When I saw that Google’s Flight Deals was in beta, I was excited to use it, but it still sucks.

Finding the best flights for you seems like a good task for AI, but it’s still bad. Regular LLMs like ChatGPT or Claude do a bad job of pulling real and accurate flight prices. And AI travel booking tools like Flight Deals still suck.

Let me show you what I mean.

All of these were more expensive than what I easily found on the sites I’ve talked about.

So Which Flight Search Engine Should You Use?

There isn’t one “best” flight search engine. There’s a best tool for the stage you’re in and the type of trip you’re taking. Here’s how I actually use them: Here’s the updated table with Omio added:

Tool	Best For	I Use It When…	I Don’t Use It For…
Kiwi	Flexible backpackers & multi-airport searches	I’m open to multiple departure cities or destinations and want to see unusual route combinations	Final booking or tight self-transfers
Momondo	Inspiration & “Where can I go?” searches	I know my dates but don’t care about the destination	Precision filtering or baggage comparisons
Skyscanner	Whole-month flexibility	I’m flexible by weeks and want to instantly see the cheapest days in a month	Final price confirmation
Omio	Comparing flights vs. trains vs. buses	I’m not sure whether to fly and want to see ground transport options side by side	Flight-only searches
Google Flights	Precision & final decision-making	I’m narrowing in on a route, checking baggage rules, tracking price history, or ready to book	Discovering ultra-weird or stitched-together routes

The Real Secret to Cheap Flights (It’s Not the Tool)

By now, this should be clear:

There is no flight search engine that magically unlocks secret fares.

The reason I consistently find cheap flights has more to do with how I travel.

It comes down to two things.

1. Be Flexible

Flexible dates. Flexible airports. Flexible routes. Flexible with the airlines. If you’re scared of budget airlines, see how to make them work for you in this article.

The cheapest flights almost never leave on Friday afternoon or land exactly where you want. They almost never leave during peak tourist season.

Flexibility is your leverage.

2. Pack Light

Packing light unlocks budget airlines.

Budget airlines are where the biggest deals live.

When everything fits in a backpack or personal item, you avoid baggage fees, gain more routing options, and can take advantage of fares most travelers can’t touch.

The tools just help you see what flexibility and packing light make possible, and help make sure you know all the best options available to you.

If you want a deeper, step-by-step breakdown of how I routinely save hundreds of dollars on flights by changing how I travel I go much deeper in my ebook.