LiteLLM vs OpenRouter: LLM Gateways Comparison
Compare LiteLLM and OpenRouter side by side. Both are tools in the LLM Gateways category.
Updated April 29, 2026
The short answer
Choose LiteLLM if free open-source core with MIT license.
Choose OpenRouter if largest model catalog in the gateway space — 300+ models.
How they actually differ
LiteLLM and OpenRouter both let you call many LLM providers through one endpoint but they ship as different products and the choice between them reduces to whether you want to run infrastructure or pay for it.
LiteLLM is open-source software (and a paid hosted tier) from BerriAI. The core library translates your code between provider SDKs so a single OpenAI-format call works against Anthropic, Bedrock, Vertex, Mistral, Together, and ~100 others. The LiteLLM proxy server adds the gateway features on top: load balancing, retries, fallbacks, caching, virtual keys, cost tracking. You self-host it (Docker, Kubernetes, anywhere) and you pay providers directly. The trade-off is you carry the operational burden. The win is no marketplace margin and full data control.
OpenRouter is a hosted marketplace. You fund a wallet, get one API key, and call 300+ models through their OpenAI-compatible endpoint. They handle billing across providers, you don't manage individual provider relationships. The trade-off is that you are paying OpenRouter's margin on every call (typically 5 to 10 percent over the underlying provider price) and you are dependent on their availability and policies.
Where the trade-off bites: LiteLLM wins on cost at scale (no margin), on data control (no third party in the path), and on customization (you can fork the proxy if needed). OpenRouter wins on time-to-first-call, on access to long-tail models you would not provision provider accounts for, and on small-team simplicity.
Where Respan fits. Respan is the third option that bundles both modes. Hit our gateway with one API key for the marketplace experience, or use passthrough mode with your own provider keys for the no-margin path. Either way you get tracing, prompt management, and evals on the same data model. See AI Gateway.
On the cost side, LLM cache layers covers the 3 caches a gateway should expose to be useful at scale.
Want to 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 250+ models through one gateway. Free tier covers 10K traces per month. Setup in 5 minutes, no credit card.
Quick Comparison
| Category | LLM Gateways | LLM Gateways |
| Pricing | Open Source | Free tier + pay-as-you-go (passthrough + 5.5% fee) |
| Best For | Engineering teams who want an open-source, self-hosted LLM proxy for provider management | Developers and teams who want one API for hundreds of LLMs without provider lock-in |
| Website | litellm.ai | openrouter.ai |
| Key Features |
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Pros & Cons: LiteLLM vs OpenRouter
- +Free open-source core with MIT license
- +Unified interface to 100+ LLM providers
- +18k+ GitHub stars with strong community
- +Trusted by major enterprises
- −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
- +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
- −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
Pricing: LiteLLM vs OpenRouter
- · MIT license
- · Proxy server
- · 100+ LLM APIs
- · Cost tracking
- · Cloud hosting
- · DevOps labor (USD 1.5-2k/mo)
- · Monitoring tools (USD 200-800/mo)
- · Incident response
- · SSO (Single Sign-On)
- · RBAC
- · Team-level budgets
- · Compliance features
- · Access to 25+ free models
- · 50 requests/day (1,000 with $10+ credits)
- · 20 requests/minute
- · OpenAI-compatible API
- · 300+ models, 60+ providers
- · Passthrough provider rates + 5.5% credit-card fee
- · 5% fee on crypto purchases
- · Per-API-key spend tracking
What people are saying
Curated quotes from Hacker News, Reddit, Product Hunt, and review blogs. Dates shown so you can judge whether early criticism still applies.
- +
“OpenRouter adds 5% on top of the model provider's base prices — for a single API across 300+ models that's a fair tax.”
— Reddit user, Reddit / Toksta summary · Feb 2026 - +
“The ability to track cost of each request and separate usages through different API keys is huge for indie devs running side projects.”
— Hacker News commenter, Hacker News · Apr 2026 - ·
“OpenRouter claims ~25ms added latency in ideal conditions, with ~40ms typical — acceptable for most apps but noticeable on streaming.”
— Cost analysis, Costbench · Apr 2026 - −
“Free models are somewhat fragile with timeouts and require sleep between invocations — most users end up moving to paid models.”
— Honest review, Ofox.ai · Mar 2026
When to Choose LiteLLM vs OpenRouter
- Self-hosted LLM gateway for data control
- Standardizing LLM access across teams
- Budget enforcement per team or project
- Model-agnostic AI apps that swap providers freely
- Fallback routing when a primary provider is degraded
- Cost optimization across price-equivalent models
About LiteLLM
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.
About OpenRouter
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.
Two pricing tiers: a Free tier (25+ free-of-charge models, 50 requests/day, 20 RPM, raised to 1,000/day after $10+ in credits) and Pay-as-you-go (300+ models, passthrough provider rates, 5.5% platform fee on credit-card purchases / 5% on crypto). OpenRouter adds ~25-40ms latency over direct provider calls in typical conditions.
Major use cases: avoiding vendor lock-in across OpenAI/Anthropic/Google, fallback routing when a provider is down, cost optimization across price-equivalent models, and tracking spend per API key. Free credits expire after 365 days. As of 2026, OpenRouter is the most-used model gateway for AI startups and indie developers building model-agnostic applications.
What is LLM Gateways?
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.
Browse all LLM Gatewaystools →Other LLM Gateways Tools
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