Which Site has the Cheapest Flights? Google, Skyscanner or KAYAK? - 60 Routes Studied

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Which flight comparison website finds the cheapest fares most often?

Important: 

This study contains two datasets: one was originally conducted in 2018, and the other in August 2026.

The 2018 results below should be viewed as a historical snapshot of how the seven flight comparison engines performed purely on first-displayed price.

We have retained the study because it provides useful first-hand evidence of how dramatically results could vary between comparison sites.

Below, we have added a further comparison study for 2026, including a few further details such as how comparison sites differed based on the number of stops chosen and whether the actual fare was shown and could be booked at the advertised price.

 

How We Conducted the 2018 Study

• London
• Manchester
• Birmingham

• Google Flights
• Skyscanner
• KAYAK
• momondo
• Cheapflights
• Jetcost
• Dohop

• the cheapest or joint-cheapest result in green; and
• the most expensive or joint-most-expensive result in red.

 

Full 2018 Results

 

Which Flight Search Engines Were Cheapest Most Often in 2018?

1. Skyscanner — 40%
2. momondo — 38%
3. KAYAK — 36%
4. Cheapflights — 35%
5. Dohop — 35%
6. Google Flights — 18%
7. Jetcost — 13%

Which Search Engines Were Most Expensive Most Often?

1. Google Flights — 53%
2. Jetcost — 35%
3. Skyscanner — 13%
4. momondo — 8%
5. Cheapflights — 8%
6. Dohop — 6%
7. KAYAK — 5%

 

Updated Comparison Study for 2026

Full 2026 Flight Comparison Results

Green = cheapest or joint-cheapest displayed fare.    Red = highest or joint-highest displayed fare.    N/A = no comparable direct fare found.

* Google Flights initially displayed a £895 direct fare for London–Minneapolis. When we checked the result more closely, the fare had changed to £963.

How Big Were the Differences?

The differences were sometimes substantial.

The most striking example was London to São Paulo, where the cheapest direct fare we found was £746 on Google Flights, while another search engine displayed a fare of £1,315 for the same route.

That is a difference of £569 — approximately 76% more than the cheapest fare found.

Other notable differences included:

• London–Tokyo direct: £327 difference between the cheapest and most expensive results.
• London–Kingston one stop: £189 difference.
• London–Minneapolis one stop: £172 difference.
• London–São Paulo one stop: £171 difference.
• London–Tokyo one stop: £125 difference.

 

Across the 19 direct or one-stop comparisons where fares could be compared, the average gap between the cheapest and highest displayed price was approximately £117.

The median difference was £73.

This means the particularly large discrepancies were not isolated to one route, although some journeys — such as London to Phuket — produced very similar results across almost every search engine.

No Search Engine Was Consistently Cheapest

Perhaps the most important result was that there was no universal winner.

Google Flights produced the lowest displayed fare on some routes.

Skyscanner won others.

KAYAK and momondo were cheapest or joint-cheapest on several searches, while Jetradar and Skiplagged also produced the lowest fare on individual routes.

Even within the same journey, the best search engine could change depending on whether we looked at a direct or connecting flight.

For example:

London to Tokyo

• Cheapest direct: momondo / Skiplagged — £1,288
• Cheapest one stop: Skyscanner — £771

London to São Paulo

• Cheapest direct: Google Flights — £746
• Cheapest one stop: KAYAK — £711

London to Phoenix

• Cheapest direct: KAYAK / momondo — £745
• Cheapest one stop: Skiplagged — £722

That makes it difficult to justify relying permanently on any single flight comparison website if finding the lowest price is the priority.

The Cheapest Displayed Fare Wasn't Always the Cheapest Bookable Fare

There was another important issue that a simple price table cannot show.

Our study recorded the lowest prices initially displayed by the comparison engines. It was not intended to certify every result as a successfully bookable fare.

During our checks, we encountered cases where:

• a fare disappeared after clicking through;
• the price increased at the booking stage;
• the initial result appeared to be a phantom or stale fare;
• or the cheapest result was offered by a relatively small online travel agency that travellers may wish to investigate further before booking.

One example occurred on London to Minneapolis.

Google Flights initially displayed a direct fare of £895, but when the fare was checked more closely, the price was actually £963.

This highlights an important distinction:

The cheapest fare displayed by a flight search engine is not necessarily the cheapest fare you can successfully book.

Price Isn't the Only Thing Travellers Should Compare

Another complication is the identity of the company actually selling the ticket.

Flight comparison websites frequently redirect travellers to:

• airlines;
• major online travel agencies;
• smaller specialist agencies;
• or booking businesses that may be unfamiliar to the traveller.

 

• Customer reviews;
• Trustpilot or similar review sites;
• cancellation and change policies;
• baggage conditions;
• customer-support options;
• payment protection;
• and whether the final checkout price still equals the originally advertised price.

 

What Did Our 2026 Study Show?

1. Prices can vary dramatically between comparison engines

2. No single flight search engine consistently found the cheapest fare

3. The headline price isn't necessarily the final price

4. The cheapest seller isn't necessarily the seller you will want to book with

 

Our Main Takeaway

1. Compare several leading flight aggregators.
2. Identify the cheapest realistic fares.
3. Click through and confirm that the advertised price is still available.
4. Check exactly who will issue or sell the ticket.
5. Research unfamiliar booking providers before paying.
6. Compare the final price, baggage allowance, ticket conditions and level of consumer confidence before choosing where to book.

Compare the comparison sites — then compare the booking providers behind the prices.

 

Why FlightsFinder Compares the Comparison Sites

 

Conclusion