OpenRouter Raises $40 Million from Andreessen Horowitz and Menlo Ventures 

"Jagged intelligence" that’s how AI researcher Andrej Karpathy describes the uneven behavior of modern large language models (LLMs), where a system can solve Olympiad-level math problems in one moment and fail a basic logic test the next. 

OpenRouter, a startup founded in April 2023 by Alex Atallah and Louis Vichy, has raised $40 million across seed and Series A rounds to help developers navigate that chaos. Its platform offers a single API to route prompts across hundreds of proprietary and open-source AI models, abstracting away the complexity of switching between vendors like OpenAI, Anthropic, Meta, and dozens of cloud GPU providers.

The seed round, led by Andreessen Horowitz in February, was followed by a $28 million Series A led by Menlo Ventures in April. Sequoia Capital and angel investors including Dylan Field, Tobi Lütke, and Ashton Kutcher also participated. The company is now valued at approximately $500 million, according to a person familiar with the deal. Atallah declined to comment on the valuation.

Atallah started the company after a simple but crucial question: Will inference become a winner-take-all market? In the early months of 2023, OpenAI dominated, but Atallah noticed growing developer frustration not just over cost, but over moderation policies and model behavior.