The race for AI tenants is turning into a two-city contest. San Francisco and New York have both landed a series of large leases from artificial intelligence companies this year, with some of the biggest players expanding their footprints in both markets. Anthropic is leading the charge on both coasts. The AI giant signed a 466,000-square-foot full-building lease at AEW Capital Management’s 330 Hudson Street in July, the largest AI lease in New York City so far this year, according to CompStak data. In San Francisco, it inked a 413,000-square-foot full-building lease at 300 Howard Street in February, followed a few months later by another 250,000-square-foot lease at 500 Howard Street. That gives Anthropic more than 1.1 million square feet of new space across the two markets this year alone, per CompStak. The 300 Howard Street lease had a starting rent of $87 per square foot, per CompStak. The average starting rent for AI tenants so far this year in the combined San Francisco and Bay Area markets is $77 per square foot. Anthropic’s rent in New York was not disclosed, but the average asking rent for AI tenants so far in 2026 is about $82.83 per square foot, per CompStak. But many are paying more. Tech companies inked 69 leases with rents over $100 per square foot since the beginning of 2025, per JLL data. “Tech was drawn to Midtown South because it was cool and cheaper,” said JLL’s Kevin Kelly. “Now, due to a combination of demand for space and people being aware of what Midtown South has to offer, there’s no discount on what they’re taking down.” AI tenants in San Francisco have leased more square footage in this year’s biggest deals. Taken together, the five largest AI leases in San Francisco and the Bay Area totaled about 1.38 million square feet. New York’s five largest deals amounted to roughly 1.08 million square feet. In the largest West Coast deals, OpenAI leased 282,000 square feet at 1800 Owens Street, while Sierra AI took 258,000 square feet at 185 Berry Street. Databricks signed for another 180,000 square feet at 100 Altair Way in the Bay Area, according to CompStak. New York’s biggest deals after Anthropic include Ramp’s 285,000-square-foot extension and expansion at 28-40 West 23rd Street, Tennr’s 125,000-square-foot lease at 345 Hudson Street and EliseAI’s 109,000-square-foot deal at 401 Fifth Avenue. Legora rounded out the top five with a 98,000-square-foot lease at 11 Madison Avenue, per CompStak. The numbers offer a snapshot of the competition between the country’s two biggest markets for a generation of AI companies that are rapidly scaling their office footprints. In San Francisco, AI companies have accounted for 30 percent of leasing activity, or roughly 10 million square feet, since 2023, according to CBRE data. In Manhattan, AI companies leased 4.1 million square feet during that period, per CBRE. But the Bay Area is far more reliant on AI to drive office demand. AI companies accounted for nearly half of all office leasing by square footage in San Francisco so far in 2026, said CBRE’s Colin Yasukochi.