Router compare
RouteLLM vs vLLM Semantic Router
Router-vs-router comparison for integration shape, routing policy, target providers, pricing model, and data handling. Use this view for the routing layer; use model compare when choosing the model itself.
LMSYS (lm-sys)
Open-source LLM routing framework from LMSYS that routes simpler queries to a cheaper weak model and harder ones to a stronger frontier model, achieving 35–85% cost reduction on benchmarks.
Red Hat / vLLM Project
Open-source Mixture-of-Models router that semantically classifies each request and routes it to the best backend (local, private, or frontier) by cost, latency, privacy, or safety, deployed as an Envoy External Processor.
Facet comparison
Type
RouteLLM
Router
vLLM Semantic Router
Router
Openness
RouteLLM
Open source
vLLM Semantic Router
Open source
Hosting
RouteLLM
Self-hosted
vLLM Semantic Router
Self-hosted
Decision mechanism
RouteLLM
Predictive learned, Cascade
vLLM Semantic Router
Classifier, Semantic k-NN
Optimizes for
RouteLLM
Cost, Quality
vLLM Semantic Router
Cost, Latency, Privacy
Routing scope
RouteLLM
Binary pair
vLLM Semantic Router
Cross-provider, Cross-host
Pricing
RouteLLM
Free OSS
vLLM Semantic Router
Free OSS
Data retention
RouteLLM
Zero retention
vLLM Semantic Router
Zero retention
Models reachable
RouteLLM
-
vLLM Semantic Router
-
API compatibility
RouteLLM
OpenAI
vLLM Semantic Router
OpenAI