LiteLLM vs OpenRouter (2026): Self-Hosted Proxy or Hosted Marketplace?
Updated April 29, 2026
How they actually differ
LiteLLM and OpenRouter both let you call many LLM providers through one endpoint but they ship as different products and the choice between them reduces to whether you want to run infrastructure or pay for it.
LiteLLM is open-source software (and a paid hosted tier) from BerriAI. The core library translates your code between provider SDKs so a single OpenAI-format call works against Anthropic, Bedrock, Vertex, Mistral, Together, and ~100 others. The LiteLLM proxy server adds the gateway features on top: load balancing, retries, fallbacks, caching, virtual keys, cost tracking. You self-host it (Docker, Kubernetes, anywhere) and you pay providers directly. The trade-off is you carry the operational burden. The win is no marketplace margin and full data control.
OpenRouter is a hosted marketplace. You fund a wallet, get one API key, and call 300+ models through their OpenAI-compatible endpoint. They handle billing across providers, you don't manage individual provider relationships. The trade-off is that you are paying OpenRouter's margin on every call (typically 5 to 10 percent over the underlying provider price) and you are dependent on their availability and policies.
Where the trade-off bites: LiteLLM wins on cost at scale (no margin), on data control (no third party in the path), and on customization (you can fork the proxy if needed). OpenRouter wins on time-to-first-call, on access to long-tail models you would not provision provider accounts for, and on small-team simplicity.
Where Respan fits. Respan is the third option that bundles both modes. Hit our gateway with one API key for the marketplace experience, or use passthrough mode with your own provider keys for the no-margin path. Either way you get tracing, prompt management, and evals on the same data model. See AI Gateway.
On the cost side, LLM cache layers covers the 3 caches a gateway should expose to be useful at scale.
Overview
LiteLLM is an open-source LLM gateway and Python SDK from BerriAI that puts 140+ providers behind one OpenAI-compatible API you host yourself.
OpenRouter is an LLM gateway with one OpenAI-compatible API for 500+ models from 80+ providers, billed at provider rates plus a platform fee.
Key features
Core capabilities each platform advertises.
- OpenAI-compatible proxy for 140+ providers
- Virtual keys scoped to users and teams
- Budgets, rate limits, and spend tracking
- Fallbacks, retries, and load balancing
- Guardrails for PII masking and prompt injection
- One OpenAI-compatible API for 500+ models from 80+ providers
- Auto-routing across providers
- Budgets and management API keys
- Prompt caching
- Bring your own keys, fee-free up to $25,000 a month
Strengths and tradeoffs
What each tool does well, and the limitations to keep in mind.
Pros
- MIT-licensed proxy, free at any volume
- 140+ providers behind one OpenAI-compatible API
- Virtual keys and budgets per user and team
- Runs inside your own infrastructure
Cons
- You run, scale, and secure the proxy yourself
- Two PyPI releases were compromised in a March 2026 supply chain attack
- SSO, RBAC, and audit logs require the Enterprise license
- Tracing and evals depend on separate tools
Pros
- One key and one bill across 80+ providers
- Model calls billed at provider rates
- Free plan for prototyping on free models
- BYOK fee-free up to $25,000 of list-price inference a month
- Broadcast sends request traces to tools like Langfuse and Datadog
Cons
- Platform fee of 5.5% on Standard and 8% on Business, with a $0.80 minimum on card purchases
- Doesn't score or evaluate outputs, so quality checks happen in another tool
- Credits may be expired one year after purchase
- Free plan capped at 50 requests a day until you've bought $10 in credits
LiteLLM or OpenRouter — which should you choose?
Choose LiteLLM if you wantChoose if you want
- Self-hosted LLM gateway for data control
- Standardizing LLM access across teams
- Budget enforcement per team or project
- Switching providers without code changes
- Issuing scoped API keys to internal users
Choose OpenRouter if you wantChoose if you want
- Building model-agnostic apps that switch providers freely
- Accessing many providers with one key and one bill
- Comparing models side by side from a single API
- Tracking spend per API key
- Prototyping on free models
Compare the models
How LiteLLM's and OpenRouter's models score on public benchmarks, and their live API status.
Compare LiteLLM and OpenRouter on your own traffic
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 1,000+ models through one gateway.
Try Respan free