Fly into one city, fly home from another. Done well, an open-jaw trip is cheaper than a round trip and a better itinerary - you see two cities without backtracking. Here's how the pricing works, how to search for them, and where the savings quietly leak away.
What "open-jaw" actually means
An open-jaw itinerary has a gap in it: you fly A → B, travel overland to C, then fly C → A. On a map the route looks like an open jaw - two flight legs that don't meet at the far end. Classic examples: land in Milan, come home from Venice; land in Prague, come home from Vienna; land in Tokyo, come home from Osaka.
The overland middle (B → C) is yours to arrange - train, bus, ferry, or a rental car dropped off one-way. That's not a bug; it's usually the best part of the trip.
Why it can beat a round trip
Airline pricing is per-route, not per-region. Two airports 250 km apart can sit on completely different fare curves for the same week: one has a budget carrier flooding the route with seats, the other doesn't; one has a fare war on, the other a monopoly. A round trip locks you into one city pair for both directions - you pay the worse of the two curves twice.
An open-jaw decouples the two directions. You take whichever inbound is cheap and whichever outbound is cheap, even when they're different cities. Concretely, suppose you're pricing a September week in northern Italy (numbers are illustrative):
Itinerary
Out
Back
Total flights
Round trip via Milan
€60
€140
€200
Round trip via Venice
€120
€70
€190
Open-jaw: into Milan, home from Venice
€60
€70
€130
Add a ~€25 train between the cities and the open-jaw is still ~€45 cheaper - while turning one destination into two and saving you the half-day of backtracking to your arrival airport.
How to search for open-jaw fares
Most flight search engines treat open-jaw as an afterthought buried in "multi-city" forms that want exact dates and exact airports up front. That kills the whole point - the value of open-jaw comes from letting the two cities float to wherever the fares are low. A better process:
Search a region, not a city. Give the search several possible arrival/departure cities (or a whole country) and let it pair them. In WRVR, type "Italy" or several city codes in the To box; the engine pairs every inbound with every outbound and ranks the combinations - a round trip is just the special case where they match.
Add a nearby-airport radius. Widen each city with airports within, say, 250 km. An arrival in Prague can then pair with a departure from Vienna or Bratislava without you listing them by hand.
Keep the dates loose. Open-jaw savings multiply with date flexibility, because each leg independently finds its cheap day. A whole-month window with a 5-9 night range gives the search hundreds of leg pairings to price. (More on this in the flexible dates guide.)
Compare against both round trips. Always sanity-check A↔B and A↔C round trips. Open-jaw usually wins on flexible short-haul, but not always - long-haul round trips are sometimes priced below two one-ways.
Pricing the ground gap honestly
The overland leg is where paper savings die. Fold in all of it before deciding:
Transport cost and time. A €25, 2-hour train between your two cities is a clear win. A €150 flight or an 8-hour bus may not be. As a rule of thumb, an open-jaw needs to save more than the ground leg costs plus something for the hassle.
Where the gap sits in the trip. The best open-jaws make the ground leg part of the itinerary - you were going from Milan to Venice anyway. If you'd have to make a special journey just to catch the flight home, count that day as a cost.
Luggage and check-in reality. Two one-way tickets usually means two baggage fees and no through-checking. Budget-carrier bag fees can be €25-60 per leg.
One-way car rentals often carry a drop-off fee between cities (commonly €30-150 domestically, much more across borders). Trains and buses don't.
WRVR shows the straight-line distance of the gap on every open-jaw result, and the expanded card links a search for the connecting hop - but the ground leg's price and practicality are yours to judge.
Common mistakes
Booking the legs at different times. Two one-ways are two separate contracts. If you book the outbound now and wait a week on the return, you're exposed to the return fare rising. Decide, then book both.
Ignoring no-show rules on returns. This mostly bites people trying to skip legs of a round trip, but know it: on a single round-trip ticket, missing the outbound usually cancels the return. Two one-ways never have this problem - each stands alone.
Forgetting visas and onward-travel checks. Some borders ask for proof of onward travel; an open-jaw satisfies it (you hold a departure ticket), but from a different city - have both bookings easy to show.
Over-stretching the jaw. A 600 km gap between arrival and departure city turns your trip into a transit exercise. The sweet spot is usually 100-350 km - one comfortable train ride.
Quick checklist
Two candidate cities (or a region) rather than one fixed destination
Date window + nights range, not exact dates
Ground leg: under ~4 hours and meaningfully cheaper than the flight saving