Airbnb now has more listings worldwide than the top five hotel brands combined

Airbnb has reached a new milestone: 4 million listings worldwide.

The San Francisco-based startup now offers listings in 191 countries, and its total number of listings is higher than the top five major hotel brands combined.

The US remains Airbnb's biggest market with 660,000 listings, followed by France, Italy, Spain, and the UK. Airbnb's number of US listings puts it in fifth place among the top hotel brands in the country.

Airbnb has also seen an uptick in the number of guests using Instant Book, a feature the company first introduced in 2010 that allows guests to book a stay with one click rather than submitting a reservation request to a host. Now, 1.9 million of Airbnb's listings are instantly bookable.

The company recently had its biggest night of the year on August 5 when more than 2.5 million people stayed using the service.

Airbnb is currently the second-highest valued startup in the US. While the startup has run into legal trouble in San Francisco and New York City in the last year, it raised a massive $1 billion funding round in March that pushed its valuation to $31 billion.