Open Models Thrive on OpenRouter, Capturing 69% of Developer API Traffic

The article exposes the real tension between open and closed models in the AI economy, using OpenRouter as a proxy for the developer API frontier.

While open models remain a fraction of total inference, their usage on OpenRouter has surged sharply since 2025, now generating 69.1% of named open-versus-closed token volume.

This shift reveals that developers are increasingly willing to route production traffic to open-weight models, driven by rapid price-performance competition and the ability to switch models instantaneously.