Respan vs Vercel AI Gateway: LLM Gateways Comparison

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.

The platform provides intelligent model routing with automatic fallback strategies, ensuring AI applications stay online even when individual providers experience outages. Built-in load balancing distributes requests across providers for optimal performance, while real-time cost tracking and usage analytics help teams understand and control their AI spend. Respan's caching layer reduces redundant API calls, cutting costs by up to 70% for repeated queries.

Respan also includes rate limiting, request/response logging, and a unified dashboard for monitoring all LLM interactions across an organization. The platform supports prompt management, A/B testing between models, and semantic caching to accelerate response times. Teams can get started with a free tier and scale to enterprise plans with custom SLAs and dedicated support.

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.