Best LLM gateways in 2026

An LLM gatewaysits between your app and the model providers, giving you one API for many models plus routing, failover, and cost controls. The category has matured fast, so here's a practical, current comparison of the leading options and how to choose.

How to evaluate an LLM gateway

• Model coverage — how many providers and models, behind one API
• Routing intelligence — does it optimize per request by cost, quality, and latency, or just proxy?
• Observability — can you see why each request routed where it did, and what it cost?
• Governance — budgets, quality floors, data residency, per-key controls
• Operational model — managed service vs. self-hosted proxy

The leading LLM gateways

Neural Router

A managed, OpenAI-compatible gateway focused on decision-level routing: every request is routed to the best model by cost, quality, and latency, and returns a receipt showing the candidates, scores, constraints, and final choice. Best for production teams that need routing they can audit, plus budgets, quality floors, and residency enforcement.

OpenRouter

A popular managed aggregator that unified access to hundreds of models behind one key and endpoint. Great for reaching many models quickly. See our OpenRouter comparison for where a routing-and-governance layer adds more.

LiteLLM

A widely used open-source proxy and SDK that normalizes providers into an OpenAI-compatible format. Best when you want to self-host and control everything; you write and maintain the routing rules. See LiteLLM vs Neural Router.

Portkey

A gateway with a strong emphasis on observability and guardrails alongside routing and caching. A good fit for teams that lead with monitoring and prompt management.

Braintrust Gateway

A unified API bundled with Braintrust's evaluation tooling — attractive if you already run your eval and experimentation workflow there.

Quick comparison