Can a flight booking API show me flights from low cost airlines as well as the regular ones?

Yes, in most cases, but it depends on which suppliers your API is connected to. Traditional airlines usually come through the global systems agents have used for years, while low cost carriers are added separately, either straight from the airline or through an aggregator that gathers several of them in one place. So low cost content is available, but it is not automatic, and it has to be switched on for your account.

When it is switched on, those flights appear in your search results alongside the others, so your customer sees one list and picks whatever suits them. Behind the scenes they do not all behave the same way. Many low cost airlines sell a bare fare and charge separately for baggage, seats and meals, so those extras come back as options you add during booking rather than being part of the fare. Several of them also take payment at once with no option to hold, and their change and cancellation rules are usually stricter.

There are real limits worth knowing before you plan around it. Not every low cost airline is reachable through every supplier, and coverage varies a lot by region, so an airline that matters in your market may or may not be included. Putting a low cost flight and a traditional airline on one ticket is often not possible, and it would instead be two separate bookings that you look after side by side. Changes after the sale, such as a new date, sometimes have to be handled with the airline directly.

The useful next step is to write down the low cost airlines your customers ask for most often, then we can check which of them your supplier setup already covers and what adding the others would involve.