The best LLM router depends on what you want routed: OpenRouter is the biggest catalog router (300+ models, you pick the model or set fallback chains, pay-as-you-go with a ~5.5% credit fee), Standard Compute is the flat-rate smart router (it picks the model per request — frontier on hard work, efficient models on routine work — for a fixed monthly price), and self-hosted classifiers like RouteLLM suit teams that want routing logic they control. Cursor and Copilot also route internally, but only inside their own products.
Most products called an LLM router are catalog routers: one API in front of many models, but you still decide which model handles each request (or define a static fallback order). OpenRouter is the reference implementation — enormous catalog, transparent list prices, provider failover.
A smart router decides per request. It classifies the work and sends hard tasks to frontier models and routine tasks to efficient ones. That is what Standard Compute does behind one model id, and what open-source projects like RouteLLM let you build yourself if you are willing to host and tune a classifier.
| Router | Type | Price model | The catch |
|---|---|---|---|
| OpenRouter | Catalog + fallbacks | Pay-as-you-go, ~5.5% fee on credit purchases | You still pick models; per-token bills spike with agent loops |
| Standard Compute | Smart routing, one model id | Flat monthly plans from $19 | You do not pin model versions — the router picks |
| RouteLLM (self-hosted) | Smart, DIY | Free software + your infra + API keys | You maintain the classifier and the quality bar |
| Cursor / Copilot internal routing | Smart, closed | Their subscription | Only routes inside their product; credits still meter usage |
Watch the router's incentive. A per-token router earns more when you spend more tokens, so it has no reason to route your work to cheaper models. A flat-rate router earns more when routing is efficient — its incentive is to give you the cheapest model that still does the job well. Neither incentive is neutral; pick the one aligned with your bill.
Standard Compute is the flat-rate option in this list: one OpenAI-compatible endpoint, one model id (standardcompute), smart routing across closed frontier and efficient open models, from $19/mo with a fixed monthly compute budget and no per-token meter. If you mostly want routing so your agent bill stops surprising you, that is the shortest path.
Not by default. OpenRouter gives you one API over 300+ models with provider failover and optional fallback chains, but you (or your tool) choose the model. It added auto-routing options, but the core product is a catalog with pass-through pricing plus a ~5.5% fee on credit purchases.
It can if the router is tuned to save money at any cost. The honest trade: you give up pinning a specific model version, and in exchange routine requests stop costing frontier prices. Judge a router by whether hard tasks still land on frontier models — ask for eval details or test with your own workload.
For light use, OpenRouter's free-model tier (rate-limited) costs nothing. For sustained agent workloads, flat-rate routing is usually cheaper than per-token: a typical agentic coding month burns hundreds of thousands to millions of tokens, which meters badly but budgets well.