“Twenty years ago, parents chose the matches,” Mr. Janakiraman said of those who have embraced technology in the marriage hunt. “Now parents are largely playing supporting roles, and the brides and grooms are in the driver’s seat.”

But even as social mores shift, relatively few young Indians, including those who demand more of a say in their marriages, are straying too far from tradition. Dating — or at least openly dating with parents’ consent — is still relatively rare. And many of those who choose semi-arranged marriages say that romantic love, the head-spinning Bollywood kind, is not their goal. Compatibility is, as is a sense of control over one’s destiny.

“I wouldn’t say that I’m head-over-heels madly in love with my husband,” said Megha Sehgal, a flight attendant. “But he gives me a lot of comfort, and I see a friend in him.”

The percentage of semi-arranged marriages has grown to an estimated quarter of all marriages in India, according to a survey, while just about 5 percent of matches are considered “love marriages,” in which couples unite with little parental consent. The survey was conducted by the International Institute for Population Sciences and the Population Council.

Indeed, many families involved in both old and new forms of arranged marriages see falling in love before marriage as threatening. Those with money sometimes hire private investigators to ensure that a prospective spouse does not have any ill intentions or has not already fallen in love then broken off that relationship in favor of an approved match.

“Fifteen years ago, most of my investigations revolved around checking out the family,” said Sanjay Singh, a private detective in Delhi. “Now they’re mostly concerned with whether the other person is already involved with someone else.”

For poor, rural women, the notion of even semi-arranged marriage is still mainly out of reach — a fact that human rights activists say leaves girls especially vulnerable.