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OpenRouter

OpenRouter is a unified API gateway that gives developers one key and one bill for 400+ AI models from every major provider.

What is OpenRouter?

OpenRouter is a unified API that gives developers one key to access more than 400 large language models from every major AI provider, including OpenAI, Anthropic, Google, Mistral, and dozens of open-source labs. Instead of building and maintaining separate integrations for each provider, a developer connects once and switches models by changing a single parameter. That matters for anyone building production AI systems, because it removes the lock-in risk of betting an entire product on one model provider’s uptime, pricing, or roadmap.

How OpenRouter works

OpenRouter sits between your application and the AI model providers, acting as a single routing layer. Your app sends a request to OpenRouter’s API, OpenRouter forwards it to whichever model you specify, and it returns the response in a consistent, normalized format.

Unified endpoint: the API is a drop-in replacement for the OpenAI API. You change the base URL and API key, and existing code keeps working.
Model switching: you swap from one model to another, for example GPT to Claude, by changing one field in your request. No new SDK, no new auth flow.
Automatic routing: an auto router or custom fallback rules can send a request to a backup model if your first choice is down, over capacity, or too slow.
Unified billing: one credit balance and one dashboard track spend across every provider you use, instead of juggling separate invoices.
BYOK support: if you already have API keys with specific providers, you can route through OpenRouter while still billing directly to your own accounts.

What you can build with OpenRouter

Model comparison tooling: run the same prompt against GPT, Claude, Gemini, and open-source models side by side to decide which one actually performs best for your use case, without rewriting integration code for each.
Cost-tiered agent pipelines: build an agent that tries a cheap, fast model first and escalates to a more expensive, more capable model only when the task demands it, cutting inference costs without sacrificing quality on hard requests.
Multi-agent systems: orchestrate a pipeline where a strong reasoning model handles planning and cheaper models handle execution steps, with OpenRouter managing the routing between them.
Resilient production apps: ship an AI feature that keeps working even if one provider has an outage, because OpenRouter can fall back to an alternate model automatically.
Prototyping and experimentation: test an idea across a dozen models during development using the free tier, then lock in the best-performing model before launch.

Key Features

  • One API key for 400+ models across every major provider
  • Drop-in OpenAI-compatible endpoint, no code rewrite needed
  • Automatic fallback routing if a provider goes down or hits capacity
  • Side-by-side pricing and performance comparison across models
  • Free tier with 25+ no-cost models and daily request allowance
  • Bring-your-own-key support for existing provider accounts

FAQ

Is OpenRouter free to use? +

OpenRouter gives every new account a small free credit allowance and offers 25 or more no-cost models. Free usage is capped at 50 requests a day and 20 a minute, which works for testing but is too limited for production traffic that needs consistent throughput.

How does OpenRouter make money? +

OpenRouter charges a small percentage fee, typically around 5.5 percent, on credits purchased through its platform. It does not mark up the underlying model provider's price. For bring-your-own-key usage past a free monthly threshold, it charges roughly 5 percent of the equivalent platform cost.

Can I switch AI models without changing my code? +

Yes. Because OpenRouter exposes an OpenAI-compatible endpoint, you switch models by changing a single parameter in your request rather than rewriting your integration. This lets you compare providers or fail over to a backup model with minimal engineering work.

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