The best flight search engines don’t all find the same prices — and that difference can mean hundreds of pounds on a single booking. Each tool has different airline partnerships, search algorithms, and hidden features that make it better or worse for specific types of searches. Knowing which engine to reach for, and when, can consistently save you money compared to always using the same platform.

1. Google Flights – Best for Flexible Searches

Google Flights is the starting point for most savvy travellers, and for good reason. Its calendar and price grid views make it effortless to find the cheapest dates across an entire month. The “Explore” map lets you search by budget without a specific destination — perfect if you’re open to wherever is cheapest.

Best for: Flexible date searches, price tracking alerts, and exploring destinations by budget.
Limitation: Doesn’t include all budget airlines, so always cross-check on Skyscanner.

2. Skyscanner – Best for Budget Airlines and Global Coverage

Skyscanner has the broadest airline coverage of any flight search engine, including many low-cost carriers that Google Flights misses. Its “Cheapest Month” view is excellent for long-range planning, and the “Everywhere” destination search is a goldmine for deal hunters.

Best for: Finding budget airline deals, searching with maximum flexibility, and global routes.
Limitation: Some third-party booking sites it links to can add hidden fees at checkout.

3. Kayak – Best for Complex Itineraries

Kayak excels at multi-city and complex routing searches. Its “Hacker Fares” feature splits your outbound and return across different airlines to find the cheapest combination — something most search engines don’t attempt. Kayak’s Price Forecast tool uses historical data to advise whether to book now or wait.

Best for: Multi-city trips, hacker fares, and price trend analysis.
Limitation: Can be slower to load than Google Flights on mobile.

4. Momondo – Best for Finding Hidden Cheap Fares

Momondo consistently turns up fares that other engines miss, particularly from smaller regional carriers and consolidators. Its visualisation of price trends over time is genuinely useful for planning, and it’s often worth checking Momondo as a final sanity check before booking elsewhere.

Best for: Discovering fares other engines miss, regional airlines.
Limitation: Interface is less polished than Google Flights; some prices require clicking through multiple pages before the final total is clear.

5. Hopper – Best for Price Predictions and Mobile Booking

Hopper‘s standout feature is its price prediction algorithm, which analyses billions of data points to tell you whether flight prices will rise or fall — and by how much. It uses colour coding to show the cheapest and most expensive dates at a glance. Hopper is a mobile-first app, making it ideal for booking on the go.

Best for: Last-minute decisions, price prediction, mobile booking.
Limitation: Focuses mainly on North American routes; international coverage is less comprehensive.

6. Aviasales – Best for Eastern Europe and Asia Routes

Aviasales is one of the largest flight search engines for Eastern European, Russian, and Central Asian routes — markets where Google Flights often has gaps. It also aggregates deals from regional Asian carriers that Western-facing tools don’t always capture.

Best for: Eastern Europe, Central Asia, routes from Russia and nearby countries.
Limitation: Less comprehensive for Western European and transatlantic routes.

Our Recommended Search Strategy

Rather than picking just one tool, use this two-step approach for the cheapest results every time:

1. Start with Google Flights using flexible dates to find the cheapest departure window and get a baseline price.
2. Cross-check on Skyscanner to catch any budget airline fares Google missed, then confirm the best price on Momondo.
3. Book directly with the airline or through the comparison site, whichever is cheaper at the final checkout stage.

Search Flights Now

Use our integrated flight search below — powered by Aviasales, which searches 728+ airlines and booking sites — to find the cheapest flights for your route right now:

More cheap flight guides: How to find cheap flights | Cheapest days to fly | Flight deal alerts