Redfin, the Seattle-based real estate brokerage, is starting a program that lets house hunters bid on properties directly through its website. The move aims to bring online shopping to a business dominated by attending weekend open houses and driving around with agents.

The company recently tested the program in Boston and now plans to extend it in stages across the country. It is the latest sign that technology companies are encroaching on the decidedly low-tech world of real estate sales.

Web-focused operations like Redfin, Zillow, Opendoor and Offerpad — along with brokerage giants like Realogy, which owns Coldwell Banker and other brands — have been building out “instant buying” programs that allow home sellers to solicit direct offers from the company. The Redfin program, Redfin Direct, is an effort to bring the approach to the other side of the transaction.

Real estate agents’ groups will be watching to see whether Redfin’s competitors introduce similar programs. At stake is the roughly $110 billion a year in commissions generated by home sales.