OpenRouter

OpenRouter positions itself as "the unified interface for LLMs" — a single API that gives developers access to more than 400 models from over 70 providers, rather than requiring separate integrations, accounts, and billing relationships with each individual AI company. Who it's for: developers and organizations building AI-powered applications who want flexibility to switch between models (or providers) without rewriting their integration each time. OpenRouter states it's used by more than 250,000 apps with millions of global users, including recognizable names like Replit and Kilo Code among its featured integrations. Strengths: an OpenAI SDK-compatible interface means many existing integrations can point at OpenRouter with minimal code changes, immediately gaining access to a much wider model catalog. Provider failover is a genuine reliability advantage — if one upstream provider has an outage, OpenRouter's distributed infrastructure can route around it rather than the whole application going down. Custom data policies let teams control which providers are allowed to see their prompts, addressing a real compliance concern for anyone routing sensitive data through third-party model providers. Prompt caching and "sticky routing" (keeping a session pinned to the same provider/model for consistency) are also included, along with audio transcription support. Weaknesses and limitations: OpenRouter operates on a credit-based purchase system (the site shows example top-ups like $10 and $99) rather than a flat subscription, and specific per-model rates aren't laid out in detail on the main marketing page — actual cost-per-token varies by which underlying model a request routes to, so budgeting requires checking model-specific pricing rather than one simple number. It's also fundamentally a routing/aggregation layer rather than a model provider itself, so it inherits the capability ceiling and occasional inconsistency of whichever upstream model handles a given request. Real-world scenarios: building an application that needs to fall back to a different model automatically during a provider outage, comparing multiple models' outputs on the same prompt without maintaining separate API keys for each, and giving a product the flexibility to swap its underlying model as better or cheaper options become available without an engineering rewrite. Compared to a single-vendor API (OpenAI's or Anthropic's directly), OpenRouter trades a small routing markup for meaningfully more flexibility and resilience.