Baseten hits $13B valuation on $1.5B Series F for AI inference

Baseten, a San Francisco-based AI inference platform, closed a $1.5 billion Series F led by Altimeter Capital, Conviction, and Spark Capital, valuing the company at $13 billion. The round was completed across two tranches at $13B and $11B valuations and represents the company's fourth fundraise in 18 months. Co-investors included Sands Capital, Wellington Management, IVP, Greylock, Blackbird, Durable Capital Partners, and others.

The funding reflects explosive demand for inference infrastructure as enterprises shift from training models to running them at scale. Baseten reported 20-fold revenue growth and 40-fold growth in inference volume over the past year, now processing over one billion inference requests daily across 87 global clusters on 18 cloud environments. The company serves customers including Cursor, Notion, Lovable, Harvey, and HubSpot.

Inference—the computational stage where trained models generate outputs in production—has become its own infrastructure category commanding investor attention at the scale previously reserved for cloud computing and semiconductors. Baseten's bet is that enterprises increasingly want to split model access (closed APIs from OpenAI/Anthropic) from the serving layer, deploying cheaper open-source models on owned infrastructure for better cost control and customization. The company is tripling headcount in 2026 to meet demand.