ALBANY, N.Y. — New York state enacted one of the nation’s toughest restrictions on Airbnb on Friday with a new law authorizing fines of up to $7,500 for many short-term rentals.

The measure signed into law by Democratic Governor Andrew Cuomo applies to rentals of fewer than 30 days when the owner or tenant is not present.

Supporters of the measure say many property owners use sites like Airbnb to offer residential apartments as short-term rentals to visitors, hurting existing hotels while taking residential units off the already expensive housing market in New York City.

‘‘Today is a great day for tenants, seniors, and anyone who values the safe and quiet enjoyment of their homes and neighborhoods,’’ said Manhattan Democratic Senator Liz Krueger, a cosponsor of the bill.

Airbnb said it would immediately file a lawsuit challenging the law.

‘‘In typical fashion, Albany backroom dealing rewarded a special interest — the price-gouging hotel industry — and ignored the voices of tens of thousands of New Yorkers,’’ said Josh Meltzer, Airbnb’s head of public policy in New York.

Enforcement of the new laws will be a challenge. Thousands of short-term apartment rentals are listed for New York City despite a 2010 law that prohibits rentals of fewer than 30 days when the owner or tenant is not present.

The new law won’t apply to rentals in single-family homes, row houses, or apartment spare rooms if the resident is present.