LiteLLM vs OpenRouter
Updated April 29, 2026
Overview
LiteLLM is an open-source LLM proxy that translates OpenAI-format API calls to 100+ LLM providers. It provides a standardized interface for calling models from Anthropic, Google, Azure, AWS Bedrock, and dozens more. LiteLLM is popular as a self-hosted gateway with features like spend tracking, rate limiting, and team management.
OpenRouter is a unified LLM gateway providing OpenAI-compatible API access to 300+ models across 60+ providers (OpenAI, Anthropic, Google, Meta, Mistral, and more). Pay-as-you-go with passthrough rates plus a 5.5% platform fee on credit purchases; free tier with 25+ models capped at 50 requests/day.
Key features
Core capabilities each platform advertises.
- Open-source LLM proxy
- OpenAI-compatible API for 100+ providers
- Budget management and rate limiting
- Self-hostable
- Automatic retries and fallbacks
- 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
- Free tier: 25+ models, 50-1,000 req/day depending on credits
- BYO API key for select providers (no markup)
Strengths and tradeoffs
What each tool does well, and the limitations to keep in mind.
Pros
- Free open-source core with MIT license
- Unified interface to 100+ LLM providers
- 18k+ GitHub stars with strong community
- Trusted by major enterprises
Cons
- Hidden operational costs (USD 200-500/mo infrastructure)
- Production latency overhead (20-40ms typical)
- Enterprise features require USD 30k annual fee
- Operational burden for self-hosting teams
Pros
- Largest model catalog in the gateway space — 300+ models
- OpenAI-compatible API drops in with zero code change
- Reasonable platform fee — 5.5% over passthrough rates
- Per-key spend tracking and isolated rate limits
- Active free tier viable for prototyping
Cons
- Adds ~25-40ms latency over direct provider calls
- Credits expire after 365 days
- 5.5% fee + $0.80 minimum charge stings on small purchases
- Free models can be flaky — timeouts and required cooldowns
LiteLLM or OpenRouter — which should you choose?
Choose LiteLLM if you wantChoose if you want
- Self-hosted LLM gateway for data control
- Standardizing LLM access across teams
- Budget enforcement per team or project
- Provider migration without code changes
- Open-source LLM infrastructure
Choose OpenRouter if you wantChoose if you want
- Model-agnostic AI apps that swap providers freely
- Fallback routing when a primary provider is degraded
- Cost optimization across price-equivalent models
- Side-by-side model comparison from a single API
- Multi-tenant apps with per-tenant spend tracking
Compare LiteLLM and OpenRouter on your own traffic
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 500+ models through one gateway.