OpenRouter: One API for All LLMs

OpenRouter is an API gateway for language models that bundles over 300 models from OpenAI, Anthropic, Google, Meta, and other providers under a single interface.¹ The interface is OpenAI-compatible.

What I appreciate most is being able to compare models directly by sending the same prompt to different LLMs and seeing the results side by side.² On top of that, you only need one API key instead of five different accounts, and billing plus logs end up in one place.