The moves were outlined in a 32-page report that serves as a blueprint for how Airbnb plans to fight discrimination on the site. Among the other changes is a new full-time anti-discrimination team of engineers, data scientists and researchers, whose job includes discerning patterns of host behavior.

“Bias and discrimination have no place on Airbnb, and we have zero tolerance for them,” Mr. Chesky wrote in a message to Airbnb users and hosts that accompanied the report. “Unfortunately, we have been slow to address these problems, and for this I am sorry.”

Airbnb’s response is designed to quiet the questions over discrimination that have threatened to cloud growth of the company, which is based in San Francisco. Founded in 2008, Airbnb has spread to more than 34,000 cities and 191 countries, where people increasingly use the service as a replacement for hotels. The continued expansion of the privately held start-up, which is valued at $25 billion, depends partly on the idea that Airbnb can be a global company, providing a broad range of people with places to stay when they travel.

That reputation was stained in December, when Harvard University researchers released a working paper that concluded it was harder for guests with African-American-sounding names to rent rooms through the site. Several Airbnb users have since shared stories on social media saying they were denied a rental because of their race. In May, an African-American Airbnb user filed a suit against the company, seeking class-action status, saying he had been denied a place to stay because of his race.

Image Laura W. Murphy, a former director of the American Civil Liberties Union’s Washington legislative office, was hired by Airbnb to compile its report. Credit... Gabriella Demczuk for The New York Times

“There have been too many unacceptable instances of people being discriminated against on the Airbnb platform because of who they are or what they look like,” wrote Laura W. Murphy, a former director of the American Civil Liberties Union’s Washington legislative office who was hired by Airbnb to compile its report.