Best LLM Gateways Tools
Unified API platforms and proxies that aggregate multiple LLM providers behind a single endpoint, providing model routing, fallback, caching, rate limiting, cost optimization, and access control.
15 tools compared · Layer 1 · Updated April 29, 2026
Top 5 LLM Gateways Tools
Ranked by community traction, recent activity, and breadth of capabilities. Tap any tool for full pros, cons, pricing, and alternatives.
Respan is a unified AI gateway that provides a single API endpoint to access 250+ LLMs from every major provider including OpenAI, Anthropic, Google, Meta, Mistral, and dozens more. Built for engineering teams that need reliability and flexibility in their AI stack, Respan eliminates vendor lock-in by enabling seamless switching between models without code changes.
- Unified LLM API with 200+ models
- Real-time cost and performance analytics
- Automatic fallbacks and load balancing
+Single API endpoint for 250+ LLMs eliminates vendor lock-in
OpenRouter is a unified LLM gateway that routes requests to the best available provider for each model, with a single API key giving access to 300+ models from OpenAI, Anthropic, Google, Meta, Mistral, Cohere, and dozens of smaller providers. It exposes an OpenAI-compatible API, so any existing OpenAI SDK code works unchanged.
- 300+ models across 60+ providers via one OpenAI-compatible API
- Automatic routing to best available provider (latency, price, uptime)
- Per-API-key spend tracking and rate limiting
+Largest model catalog in the gateway space — 300+ models
Cloudflare AI Gateway is a unified API gateway for AI applications that provides observability, caching, rate limiting, and cost tracking across multiple LLM providers. Available on all Cloudflare plans, the core gateway features are free with no per-call fees beyond the Cloudflare subscription. The platform connects popular providers like Workers AI, Hugging Face, OpenAI, and Anthropic with a single line of code, offering centralized visibility and control. Built into Cloudflare global network infrastructure, AI Gateway provides edge-level caching, request retries, model fallbacks, and analytics. The free tier includes 100,000 AI Gateway logs per month, while the Workers Paid plan starting at USD 5/month provides 1 million logs. In 2026, Cloudflare introduced Unified Billing, allowing customers to pay for third-party model usage directly through Cloudflare invoices. While the platform excels at cost-effectiveness and integration with Cloudflare existing services, it adds 10-50ms of proxy latency, lacks deep AI observability features like token-level tracing, and enforces strict log retention caps that can require manual management at scale.
- Edge-deployed AI gateway
- Caching and rate limiting
- Usage analytics
+Core features free with Cloudflare plans—no per-call gateway fees
Vercel AI Gateway is a production-ready LLM gateway that provides unified access to hundreds of AI models with built-in reliability, monitoring, and cost management. Available to every Vercel team account, the gateway offers a free USD 5 monthly credit plus pay-as-you-go pricing with zero markup on model tokens. When bringing your own API keys, Vercel charges no platform fees, offering tokens at provider list price. Vercel Agent is priced at USD 0.30 per action plus underlying token costs. The platform focuses on developer experience, enabling frontend developers to add LLM capabilities with minimal setup without managing provider-specific SDKs or credentials. Key features include unified API across providers, budget controls, usage monitoring, load balancing, and automatic failover. While praised for ease of use, transparent pricing, and reliability with automatic failover, Vercel AI Gateway faces criticism for infrastructure limitations including 504 Gateway Timeout errors for long-running agents, execution time constraints (15 seconds default, 300 seconds maximum on Pro), insufficient semantic caching relying only on HTTP headers, and vendor lock-in with custom middleware not easily portable to other platforms.
+Zero markup on tokens with bring-your-own-key—transparent pricing
LiteLLM is an open-source AI Gateway developed by BerriAI with 18,000+ GitHub stars, enabling unified access to 100+ LLM APIs through OpenAI-compatible format. Founded as a Y Combinator company with USD 1.6 million in seed funding, LiteLLM is trusted by companies like Rocket Money, Samsara, Lemonade, and Adobe. The platform provides retry and fallback logic, cost tracking, guardrails, and load balancing with MIT licensing for the core proxy. While the open-source version is free, running LiteLLM requires infrastructure costs of USD 200-500 monthly plus DevOps labor, monitoring tools, and incident response. The Enterprise version at USD 30,000 annually adds SSO, RBAC, and team-level budget enforcement. Users praise LiteLLM's unified API interface and security through open-source auditability, but note production complexity with latency overhead (20-40ms) and operational burden for self-hosting.
- Open-source LLM proxy
- OpenAI-compatible API for 100+ providers
- Budget management and rate limiting
+Free open-source core with MIT license
More LLM Gateways tools
Portkey is an AI gateway that provides a unified API for 200+ LLMs with built-in reliability features including automatic retries, fallbacks, load balancing, and caching. The platform includes observability with detailed request logs, cost tracking, and performance analytics. Portkey also offers guardrails, access controls, and virtual keys for managing LLM usage across teams.
High-performance open-source LLM gateway written in Go. Handles ~10k RPS with <10ms latency.
Helicone is an open-source LLM observability and proxy platform. By adding a single line of code, developers get request logging, cost tracking, caching, rate limiting, and analytics for their LLM applications. Helicone supports all major LLM providers and can function as both a gateway proxy and a logging-only integration.
Powers the official SDKs for OpenAI, Anthropic, and others. The de facto gateway interface layer.
Unify provides intelligent LLM routing that automatically selects the optimal model and provider for each request based on quality, cost, and latency constraints. It benchmarks 100+ endpoints across providers and dynamically routes traffic to maximize performance while minimizing costs.
Martian is an intelligent model router that automatically selects the best LLM for each request based on the prompt content, required capabilities, and cost constraints. Using proprietary routing models, Martian optimizes for quality and cost simultaneously, helping teams reduce LLM spend while maintaining or improving output quality.
Kong AI Gateway extends the popular Kong API gateway with AI-specific capabilities including multi-LLM routing, prompt engineering, semantic caching, rate limiting, and cost management.
Google Cloud's Apigee includes AI gateway capabilities for managing and securing generative AI API traffic, with model routing, token-based rate limiting, content moderation, and comprehensive analytics.
Unified LLM gateway and router with intelligent routing, automatic failover, cost optimization, and PII redaction. Access 400+ models through a single API.
Compression middleware that sits between apps and LLMs, improving output quality while reducing token costs.