LLM Reference

Directory · Routing layer

Routers & gateways

Can't pick one model? Route per request. 17 verified gateways and routers, updated daily.

17 active routers

A
AIRouter

Heureka Labs UG

RouterCommercialHosted SaaSCostQuality

Passthrough + fee

Commercial LLM router that analyzes incoming requests and routes to the optimal model for cost/quality/latency via a drop-in OpenAI-compatible API, with a privacy-preserving embedding mode that avoids sending prompt content.

RouterProvider-nativeProvider-nativeCostQuality

Passthrough

AWS Bedrock's native intelligent prompt router that routes prompts between Anthropic Claude model tiers (Haiku/Sonnet) based on predicted task complexity, with no extra per-routing charge.

RouterProvider-nativeProvider-nativeCostQuality

Passthrough

Microsoft Azure AI Foundry's native model router that uses a trained ML model to route each prompt in real time to the optimal Azure-hosted model, with Balanced/Cost/Quality mode selection and automatic failover.

H
Helicone

Helicone

GatewayOpen sourceHosted SaaSReliabilityCost

Subscription

Observability-first AI gateway with routing, caching, rate limiting, and request tracing; Apache 2.0 open-source core with a managed hosted tier for logging and analytics.

KA
GatewayCommercialSelf-hostedCostLatency

Subscription

Multi-LLM AI gateway built on Kong Gateway 3.x, adding semantic routing, load balancing, guardrails, and MCP traffic analytics as plugins over Kong's existing API management platform.

L
LiteLLM

BerriAI

GatewayOpen sourceSelf-hostedCostReliability

~100 models · Free OSS

Open-source Python SDK and proxy server that unifies 100+ LLM APIs behind a single OpenAI-compatible interface, with load balancing, cost tracking, and configurable failover.

M
Martian

Martian, Inc.

RouterCommercialHosted SaaSCostQuality

Passthrough + fee

AI-powered LLM router that analyzes each prompt in real-time to select the optimal model, targeting 20–97% cost reduction while maintaining quality; San Francisco startup reportedly nearing $1.3B valuation.

NA
Neutrino AI

Neutrino AI

RouterCommercialHosted SaaSCostQuality

Passthrough + fee

Commercial LLM router that dynamically routes each query to the best-suited model with load balancing and fallback handling, charging 3% of underlying AI spend.

ND
Not Diamond

Not Diamond

RouterCommercialHosted SaaSCostQuality

Enterprise quote

Predictive model router that determines the best LLM for each query; claims up to 25% accuracy gains and 10x cost reduction; powers OpenRouter's auto mode and is positioned specifically for coding agents.

RouterProvider-nativeProvider-nativeQualityCost

Passthrough

OpenAI's native auto-routing mode (GPT-5 Auto) that dynamically routes each API request between GPT-5 and GPT-5 Instant based on prompt complexity, with no extra charge beyond model token costs.

O
OpenRouter

OpenRouter, Inc.

HybridCommercialHosted SaaSCostQuality

~400 models · Passthrough

Unified hybrid gateway to 400+ models from 60+ providers via a single OpenAI-compatible API, with optional auto-routing that selects the best model per prompt.

P
Portkey

Portkey AI

GatewayOpen sourceHosted SaaSReliabilityCost

~1.6K models · Subscription

Production AI gateway routing to 1,600+ LLMs with failover, load balancing, semantic caching, and guardrails; Apache 2.0 core is fully self-hostable with the complete feature set.

R
Requesty

Requesty

HybridCommercialHosted SaaSCostLatency

~400 models · Passthrough + fee

AI gateway to 400+ LLM providers with intelligent routing, caching, guardrails, and governance; flat 5% markup on model costs with no subscription fee.

R
Respan

Respan (formerly Keywords AI)

HybridCommercialHosted SaaSCostQuality

~250 models · Subscription

Unified LLM engineering platform (gateway + observability + evals + prompt management) routing across 250+ models; previously Keywords AI, rebranded February 2026.

R
RouteLLM

LMSYS (lm-sys)

RouterOpen sourceSelf-hostedCostQuality

Free OSS

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.

U
Unify

Unify AI

RouterCommercialHosted SaaSCostQuality

Subscription

Benchmark-driven LLM router using a neural scorer and live runtime benchmarks refreshed every 10 minutes to route each request to the optimal endpoint across 100+ providers.

VS
vLLM Semantic Router

Red Hat / vLLM Project

RouterOpen sourceSelf-hostedCostLatency

Free OSS

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.

Popular router comparisons

Curated router-vs-router pairs for common gateway, self-hosted, provider-native, and cost-routing decisions.

OpenRouter vs Requesty

Compare routing policy, target providers, pricing model, API compatibility, and data handling.

OpenRouter vs Portkey

Compare routing policy, target providers, pricing model, API compatibility, and data handling.

LiteLLM vs Kong AI Gateway

Compare routing policy, target providers, pricing model, API compatibility, and data handling.

RouteLLM vs vLLM Semantic Router

Compare routing policy, target providers, pricing model, API compatibility, and data handling.

Azure AI Foundry Model Router vs Amazon Bedrock Intelligent Prompt Routing

Compare routing policy, target providers, pricing model, API compatibility, and data handling.

AIRouter vs Martian

Compare routing policy, target providers, pricing model, API compatibility, and data handling.