The round, led by venture capital firm General Catalyst, valued the San Francisco, California-based company at $3.3 billion.
Salesforce Ventures, chip giant Nvidia and Coatue also participated in the fundraising, which was co-led by Prosperity7 — the venture capital fund of Aramco Ventures.
The new funding comes as Together AI looks to expand its cloud platform, with plans for large-scale deployment of Nvidia Blackwell graphics processing units.
Founded in 2022, Together AI's cloud platform allows developers and researchers to train and deploy generative AI models.
Last year, the company had raised $106 million in a Salesforce Ventures-led funding round at $1.25 billion valuation. It quickly gained popularity for offering access to Nvidia's sought-after GPUs.
Together AI's platform supports more than 200 open-source models, including Meta Platforms' Llama and those from China's DeepSeek.
DeepSeek's launch of its latest low-cost AI models last month has disrupted the industry and raised doubts over the United States' lead in the race to dominate the technology.
"Recent developments in open-source AI illustrate the importance of Together AI's work in making access to models like these secure, accessible, and powerful for organizations here in the U.S. and around the world," said Prosperity7 Ventures Managing Director Abhishek Shukla.
Together AI increased its user base to more than 450,000 AI developers last year, it said.
