OpenRouter

OpenRouter is a unified LLM gateway that lets you call more than 300 large language models through a single OpenAI-compatible API and one shared credit balance. It removes the chore of issuing and tracking a separate key for every provider, fitting backend developers who want to compare and switch between models from one place. Commercial use is allowed, so you can wire it straight into a production service.

Its strength lies in breadth and operational ease. When a model or provider goes down, automatic fallback reroutes the call and reduces the risk of an outage reaching your users. Even the free tier exposes 25-plus models at up to 50 requests a day, keeping the barrier to entry low.

The limits are clear too. The pay-as-you-go tier has no minimum spend, but every credit top-up carries a 5.5% platform fee. Token rates themselves pass through provider pricing unchanged, so if you are cost-sensitive it pays to factor that top-up fee in beforehand. Because the product is closed source, you cannot self-host the gateway and must accept that all traffic flows through OpenRouter.

In short, OpenRouter suits teams that want to experiment across many models quickly and run fallback from one key. If you instead need to keep traffic inside your own infrastructure with no external hop, or want to avoid even the top-up fee, contracting directly with each provider is the better route.