A new website launched by two former Facebook engineers says it can get you cheap deals on flights from Philadelphia — if you’re flexible about when and where you’re going.

Moonfish scours flight data to find deep discounts on trips originating at Philadelphia International Airport, such as a round-trip to Barcelona for $370, or 73 percent off. The month-old start-up is entering a crowded marketplace that includes such established brands as Expedia and Kayak besides a host of recent entrants.

But unlike other flight-tracking sites, Moonfish doesn’t let users submit preferred departure dates or destinations. Instead, Moonfish identifies major deals after analyzing data on a year’s worth of upcoming flights from Philly, said co-founder George Zeng, a Wharton MBA graduate. For example, that cheap trip to Barcelona leaves and returns on specific dates in September.

“It’s a different way of traveling,” said Zeng, who worked at Facebook for four years. “We have access to a ton of flight data and we’ve analyzed it, and what we’ve realized is that in order to get really great deals on flights, you have to build in some flexibility."

Moonfish searches across all permutations of flights leaving Philadelphia to other airports at every departure and return date, Zeng said. With all of that data, Moonfish finds prices that have significantly deviated from means and medians, and flags them for users, he said. On Monday, the website linked to a round trip to Minneapolis that cost $120 (65 percent off) and another to Berlin, Germany, going for $410 (56 percent off).

Zeng wants to make Moonfish a personalized online travel agent that will recommend getaways based on users’ preferences. Zeng likened Moonfish’s trip suggestions to how Facebook matches consumers with advertisements that are relevant to them. Zeng, who worked on Facebook’s advertising tech systems, said he’s partnered with Craig Campbell, a fellow Facebook engineer who helped build the social media giant’s search engine.

“It starts helping you build a profile about why you travel," Zeng said. “Let’s say you like going on beaches. We’ll push more beach trips and vacations to you.”

Launched in March, Moonfish is available only in the Philadelphia market for now. Users can sign up for free to get access to a limited number of travel deals. A premium membership costs $1.99 a month and offers access to four times as many deals, instant access to time sensitive deals, and better personalization, Zeng said. Memberships are currently the only revenue source for the start-up, but Zeng did not say how many people are paying members or the active users.

Zeng said it’s difficult to measure how many users have booked flights through Moonfish, in part because the website routs users to other websites to buy tickets.

Moonfish consists of just Zeng, Campbell, and one other engineer, and is based in San Francisco. Zeng said he launched in Philadelphia because he has “fond memories” from his time at Wharton. It’s also where he started another company: AirCare, a health-care tech company aimed at reducing costly hospital readmissions.