Microsoft crosses $100B Azure revenue with $678B backlog amid record AI capex

Microsoft's AI-cloud business hit a milestone: Azure crossed $100 billion in annual revenue for the first time, growing 43% year-over-year on eased capacity constraints and efficiency gains. The demand signal is even larger downstream — commercial remaining performance obligations (contracted future revenue) surged 84% to $678 billion, with the portion booked beyond 12 months up 112%, indicating customers are committing to multi-year AI cloud spend.

The cost side is equally dramatic. Microsoft's 2026 capex reached roughly $175 billion, up nearly 80% year-over-year, and Q4 free cash flow fell 23.2% as AI infrastructure spending outpaced cash generation. That tension — surging bookings against surging capex — is the central question for investors: whether the RPO backlog converts to margin-accretive revenue fast enough to justify the buildout.

On adoption, Microsoft 365 Copilot now exceeds 30 million paid seats, and the company is diversifying commercial bookings beyond its flagship OpenAI partnership — including making GPT-6 Astra, Sol, and Luna available in Microsoft Foundry this week and shipping its own MAI models.

Competitively, the $678B backlog and 43% Azure growth keep Microsoft neck-and-neck with AWS in the AI-cloud race, while the Copilot seat count is the clearest enterprise-monetization proof point among the hyperscalers. The caveat is capital intensity: the 23% FCF decline shows how expensive the AI buildout is, and any demand softening would expose the leverage. What to watch: whether Azure growth holds above 40% as comparisons toughen, and how quickly the beyond-12-month RPO translates into recognized revenue.