We ran the exact same search on Google Flights, Skyscanner, Kayak, Momondo and Kiwi.com using the same dates and currency. One tool was cheaper than the rest, for a reason worth knowing. Here's what we found.
This one was almost a tie. Four of the five tools landed within about $35 of each other, and Google Flights was cheapest at $218, because it was the only tool that showed a Southwest fare on this search. Take Southwest out and the cheapest was an ordinary Frontier 1-stop around $249 to $255. The nonstop (United, about 5.5 hours) was just $263, barely more than the cheapest connection. Kiwi.com was the priciest. Prices change constantly, so treat this as a snapshot, not a permanent ranking.
Ranked by the cheapest protected connection, the safest fare to book. The badge under each tool shows how you book with it. Every term is explained under the table.
| Rank | Tool | Cheapest direct | Cheapest protected connection | Cheapest business, direct |
|---|---|---|---|---|
| 1 |  Google Flights Comparison site | $263  United · nonstop 5h 33m | $218  Southwest · 1 stop · Kansas City 9h 40m | $1,372  American · nonstop · Flagship First 5h 36m |
| 2 |  Skyscanner Comparison site | $273 United · nonstop 5h 33m | $249  Frontier · 1 stop · Dallas 14h 12m | $1,372 American · nonstop · Flagship First 5h 36m |
| 3 |  Kayak Comparison site | $280 United · nonstop 5h 33m | $255 Frontier · 1 stop · Dallas 10h 53m | $1,372 American · nonstop · Flagship First 5h 36m |
| 4 |  Momondo Comparison site | $280 United · nonstop 5h 33m | $255 Frontier · 1 stop · Dallas 10h 53m | $1,372 American · nonstop · Flagship First 5h 36m |
| 5 |  Kiwi.com Reseller | $288  JetBlue · nonstop 5h 43m | $233 JetBlue + Frontier · 1 stop · Chicago ~30h, long layovers | $1,807 JetBlue Mint · nonstop 5h 27m |
All legs on one ticket, so the airline rebooks you free if a connection is missed. The safest fare to book.
The cheapest lie-flat premium seat on a nonstop. On US domestic routes it's sold as "First", and JFK-LAS is one of the few with a real transcon Flagship product.
A comparison site shows the fares and sends you to the airline or an agency to pay. A reseller like Kiwi.com takes your payment itself and adds its own fees, so it usually costs a little more.
Why Google was cheaper: it showed a Southwest fare, and the others didn't. Southwest doesn't sell through resellers like Kiwi.com. It does list fares on Google Flights and Kayak, which send you to Southwest.com to book, but in our search only Google showed this $218 fare. On the fares they could all see, the four comparison sites were within a few dollars of each other.
A cheap fare isn't the whole price. The cheapest tickets here were bare Frontier fares that charge for a carry-on and a checked bag, sometimes $50 to $70 each way per bag. Southwest used to include two free checked bags, but it now charges for bags on its cheaper fares too. Add your bags before you compare.
The business column is the cheapest lie-flat nonstop each tool found. All four comparison sites landed on the same fare, American's JFK-LAS Flagship First at $1,372 (about five times the economy nonstop). Kiwi showed a business fare too, JetBlue Mint at $1,807, but priced above the others as usual.
Kayak and Momondo are owned by the same company and returned identical fares; we list both because people search for each. Kiwi.com showed the same flights as everyone else, the JetBlue nonstop ($288), a slow 30-hour one-stop ($233) and JetBlue Mint business ($1,807), but it's a reseller and priced each above the comparison sites, so it's ranked last. Prices are live and drift by the hour, so read the pattern, not the exact dollar.
The cheapest fares here were bare Frontier tickets. Frontier (like Spirit) charges for everything: a carry-on and a checked bag are both extra, often $50 to $70 each way, and more if you pay at the airport. A $255 Frontier fare with one bag each way is really closer to $375.
Southwest used to be the exception, with two free checked bags on every fare. Since May 2025 its cheaper fares charge for checked bags too, so its $218 needs the same bag check as everyone else's.
Even the legacy nonstops sell a stripped "Basic Economy" fare with no free checked bag, so whatever you book, add your bags before you compare and check what the fare actually includes. On a US route it changes the ranking more than the headline price does.