New Delhi, Sept. 2 -- Some of India's biggest data-centre operators are enjoying a rare combination: faster revenue growth and fatter margins. But the boom in their earnings for fiscal year 2026 (FY26) is being driven less by artificial intelligence (AI) than by existing capacity filling up.

Bharti Airtel-owned Nxtra Data, AdaniConneX, Sify Infinit Spaces and IPO-bound ESDS Software Solutions reported strong revenue growth in FY26, according to a Mint review of company filings. All four reported their fastest revenue growth and strongest operating margins in at least three years. AdaniConneX and Nxtra also recorded their sharpest operating-margin expansion in at least three years.

Together, the four account for more than a third of Indi...