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Which flight booking site is actually cheapest?

We keep hearing that one comparison tool always beats the rest. So we test it properly: the exact same search, on the same day, across every tool, on real routes. Here’s what the results say, and every test in full.

🧪 Routes tested9 so far, more coming
🔎 Tools each5: Google, Skyscanner, Kayak, Momondo, Kiwi
⚖️ Same conditionsSame dates, 1 adult, EUR, no VPN
🕒 Same sittingAll searches within ~15 min
🏆 The short answer

They're closer than you'd think. We expected one tool to dominate. It didn't. On most of the nine routes the comparison sites came out level, or within a few percent. Only the budget hops had a clear winner: Kayak on Bali and Singapore, Skyscanner on Bangkok. So don't sweat the choice, use whichever you like and check a second on cheap short-haul routes. Ours is Skyscanner. The one rule: Kiwi.com priced higher on every route and finished last on all nine, so skip the reseller.

How each tool did

Same routes, same dates, same moment, judged on the cheapest ticket we’d actually book: one booking, one airline responsible for the whole trip.

✓ cheapest or joint-cheapest · ≈ within a few percent · ✕ pricier. Read down a column to see how one tool did on every route.

✓

The three comparison tools land within a few percent of each other on almost every route. The only real split is the reseller: Kiwi.com is pricier on all nine.

Route Kayak Skyscanner Google Kiwi.com
Bali AMS → DPS ✓ ≈ ≈ ✕
Bangkok AMS → BKK ✓ ✓ ≈ ✕
New York AMS → JFK ✓ ✓ ✓ ✕
Las Vegas NYC → LAS ≈ ≈ ✓ ✕
Bali SIN → DPS ✓ ≈ ≈ ✕
Madrid BER → MAD ✓ ✓ ✓ ✕
Tokyo SYD → TYO ✓ ✓ ✓ ✕
Barcelona DXB → BCN ✓ ✓ ✓ ✕
Rio KUL → GIG ✓ ✓ ✓ ✕
Cheapest / joint 8/9 6/9 6/9 0/9
Kayak

Cheapest or joint-cheapest on eight of the nine routes, and the clear winner on the budget hops (Bali, Singapore) where a scrappy mixed-airline fare beats the majors. Momondo is the same company and matched it every time.

Skyscanner

Our pick. Never far off, won Bangkok outright, and casts the widest net for the budget airlines the others miss.

Google Flights

A fine place to start, no more reliably cheapest than the others. Clearest to read, and it hands you straight to the airline.

Kiwi.com

A reseller: the same flights, priced higher, and last on all nine. You pay Kiwi, not the airline. Skip it.

✓ Cheapest or joint-cheapest ≈ Within a few percent ✕ Pricier

Every route we’ve tested

The cheapest booking site on each route, and the one thing that stood out. Open any test to see all five tools compared side by side.

Route Cheapest site Its fare Nonstop What stood out
🇳🇱 Amsterdam → 🇮🇩 Bali AMS → DPS · tested 6 Jul 2026 Kayak €803 No nonstop exists Every tool’s cheapest fare was a risky self-transfer. Google was the priciest of the five. See the test →
🇳🇱 Amsterdam → 🇹🇭 Bangkok AMS → BKK · tested 7 Jul 2026 Skyscanner €516 KLM, from €750 Cheapest fares were ordinary protected 1-stops, not self-transfers. Kiwi finished last. See the test →
🇳🇱 Amsterdam → 🇺🇸 New York AMS → JFK · tested 7 Jul 2026 Tie — any €495 KLM/Delta, €650 All three comparison sites landed within €13 of each other on a protected Aer Lingus 1-stop. See the test →
🇺🇸 New York → 🇺🇸 Las Vegas NYC → LAS · tested 7 Jul 2026 Google Flights $218 United, $263 Google was cheapest, but only because it shows Southwest, which the others can’t. See the test →
🇸🇬 Singapore → 🇮🇩 Bali SIN → DPS · tested 7 Jul 2026 Kayak S$187 Budget, from S$187 A cheap 2.5-hour hop where the tools disagreed by 40%. Kayak and Momondo cheapest. See the test →
🇩🇪 Berlin → 🇪🇸 Madrid BER → MAD · tested 7 Jul 2026 Tie — any €209 Iberia, from €588 The tools came out close; Skyscanner cheapest on the nonstop, Google on the 1-stop. No cheap nonstop from Berlin. See the test →
🇦🇺 Sydney → 🇯🇵 Tokyo SYD → TYO · tested 7 Jul 2026 Tie — any A$1,068 Qantas, A$1,740 The comparison sites tied on the protected fare. The cheapest of all was a 53-hour self-transfer. See the test →
🇦🇪 Dubai → 🇪🇸 Barcelona DXB → BCN · tested 7 Jul 2026 Tie — any AED 1,241 Emirates, AED 3,450 The closest test of all: every comparison site showed the same Kuwait Airways fare. See the test →
🇲🇾 Kuala Lumpur → 🇧🇷 Rio KUL → GIG · tested 7 Jul 2026 Tie — any MYR 7,656 No nonstop exists The longest trip we tested: no nonstop, tools agree, and the cheapest fare is a 60-hour trap. See the test →

Momondo is owned by the same company as Kayak and returned identical fares every time, so we fold it into Kayak here; you’ll see it in each full test. Prices are live and drift by the hour, so read the pattern, not the exact figure.

1

The cheapest number is often a trap.

The very cheapest fare was usually a self-transfer: separate tickets, where a late first flight can strand you and nobody has to rebook you. Sydney to Tokyo had a 53-hour version; Kuala Lumpur to Rio a four-stop, 60-hour one that saved about MYR 90. Read the routing, not just the price.
2

Business class costs four to five times economy.

On the routes where we priced business class too, it ran a steady multiple of economy for the same flight: about four times on Singapore–Bali and Sydney–Tokyo, and five and a half on Dubai–Barcelona. Every tool showed the same business fare, so there's nothing to hunt, just a number to weigh.
So how should you actually book?
  1. 1
    Search Skyscanner (our pick) or Google Flights.
  2. 2
    Cross-check the other, or Kayak.
  3. 3
    Skip self-transfers with a tight connection.
  4. 4
    Book direct with the airline if it's only a little more.
How we test. One route at a time, in a single sitting. Same origin and destination, same return dates, 1 adult in economy, currency set to EUR on every tool, searched from a Netherlands connection with no VPN, all five searches run within about 15 minutes of each other to keep it fair. We note the cheapest fare each tool showed in each category (nonstop, protected connection, self-transfer) and rank by the cheapest protected fare, because that’s the one we’d actually book. Each route links to its full write-up above. This is a series of point-in-time snapshots; prices change constantly, so treat the figures as a reading, not a promise.
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