NeighborhoodScout, a paid service starting at $79 a month, goes deeper. Subscribers can evaluate various locations, even so-called micro-neighborhoods — there are 13,631 of them within a 50-mile radius of Midtown, according to the company — using hundreds of search criteria, including real estate data, demographics, crime rates and schools.

For many city residents, the decision to leave is difficult, and often fraught with a whole new set of compromises. You may be happily trading an overcrowded co-op for a commodious colonial, but you may have less time to enjoy it because of the long train ride home from work. And you’re responsible for maintaining it, rather than relying on a super. Forget, too, about hailing a cab to get you around town.

“We knew we had to give up something somewhere,” said Alexandra White, 34, a grant writer, who recently moved to Bedford, N.Y., in Westchester, from the Upper West Side with her husband, Nulty White, 32, who specializes in corporate branding. While she works from home, his commute to the city now takes roughly an hour and 45 minutes each way. “He doesn’t mind,” Ms. White said. “He says it’s like coming home to vacation every day.”

Once you have made up your mind to leave the city, for whatever reason, how then should you begin the journey to suburbia?

“First, think about why are you leaving,” said Alison Bernstein, the founder of Suburban Jungle, which requires clients to fill out a questionnaire before they begin their search. “Are you looking for more space? A better school system? How do you want to raise your kids? How far are you willing to commute? You need to take inventory of your family life.”

Another important consideration: where your extended family and close friends reside. “Are they going to be part of your life? This can anchor you to an area,” Ms. Bernstein said.