Honest comparison
RelayPlane vs LiteLLM vs OpenRouter
Three different answers to "how do I route and control AI model spend," for three different situations: one machine, one team, or one hosted catalog.
RelayPlane is a free, MIT-licensed local proxy: install it, set a spend cap, and it routes by task complexity across 6 native providers plus 300+ more through OpenRouter, all on your own machine with no fee added. LiteLLM is a self-hosted gateway built for platform teams, with virtual keys and per-tenant budgets across 100+ providers. OpenRouter is a hosted marketplace, no self-hosting, one API, 300+ models, with a fee on paid calls.
Feature by feature
A check means the feature ships and is documented. Where LiteLLM or OpenRouter is stronger, the table says so.
| Feature | RelayPlane | LiteLLM | OpenRouter |
|---|---|---|---|
| What it is Different shapes of the same problem: individual cost control, team gateway, or hosted catalog. | Local cost-and-control proxy for one machine | Self-hosted AI gateway for a team or org | Hosted marketplace, one API for 300+ models |
| Install OpenRouter needs no self-hosting at all; that is its main convenience. | npm install -g @relayplane/proxy | pip / uv install, run the proxy | No install, call their hosted API |
| Runs on | Your machine, localhost | A server or container you operate | OpenRouter's cloud |
| Providers reachable LiteLLM and OpenRouter both beat RelayPlane on raw provider breadth. | 6 native (Anthropic, OpenAI, Gemini, xAI, Ollama) + OpenRouter for 300+ more | 100+ providers | 300+ models, one API |
| Fee on API calls RelayPlane and self-hosted LiteLLM add no markup; OpenRouter's hosted convenience carries a fee. | ~5.5% fee on paid model calls | ||
| Model routing by task complexity RelayPlane's classifier routes down automatically by default; the others route on rules you set. | You configure routing rules | You choose the model per call | |
| Per-request cost ledger on your machine | Spend logs in the proxy database | Dashboard on their cloud | |
| Hard cap per single run, enforced before the call leaves RelayPlane scopes a cap to one job without a pre-provisioned key. LiteLLM caps at the key/team level. OpenRouter caps at the account or key level. | X-RelayPlane-Run-Cap-Usd header | Budgets per virtual key, team, or user | |
| Kill switch, halts all traffic instantly | Block a virtual key via admin API | ||
| Virtual keys, multi-tenant spend RelayPlane is single-machine by design; LiteLLM is built for this. | Per API key only | ||
| License / cost to run | MIT, free, no paid tier | OSS (MIT-style) + paid enterprise tier | Free to use, revenue via the per-call fee |
Pick RelayPlane if
- You want a hard spend cap on one machine, free
- You want automatic complexity-based routing with no config
- You are on Node.js, no Docker, no database
Pick LiteLLM if
- You need virtual keys and per-team budgets
- You need 100+ providers behind one API
- You are provisioning for a platform, not one machine
Pick OpenRouter if
- You want zero self-hosting
- You want the widest model catalog, 300+, today
- A small fee on calls is fine for the convenience
Frequently asked questions
What is the difference between RelayPlane, LiteLLM, and OpenRouter?
RelayPlane is a free, local, MIT-licensed proxy that meters cost per request on one machine and enforces hard spend caps before a call leaves. LiteLLM is a self-hosted gateway built for platform teams with virtual keys and per-tenant budgets across 100+ providers. OpenRouter is a hosted marketplace: no self-hosting, one API for 300+ models, with a fee on paid calls. They overlap on routing between models but target different users.
Which is cheapest to run: RelayPlane, LiteLLM, or OpenRouter?
RelayPlane and self-hosted LiteLLM are both free with no markup on API calls, you only pay the provider for tokens used. OpenRouter is free to start but adds roughly a 5.5% fee on paid model calls since traffic routes through their hosted API.
Can I use RelayPlane and OpenRouter together?
Yes. RelayPlane treats OpenRouter as one of its providers, so you can run RelayPlane locally for cost caps and complexity-based routing, and let it forward the long tail of models through OpenRouter when you need something outside its 6 native providers.
Which one should I pick for a solo project vs a team?
For a single developer or one machine watching its own spend, RelayPlane is built for that: install it, set a cap, done. For a platform team that needs virtual keys and per-tenant budgets across many providers, LiteLLM is the stronger fit. For the widest model catalog with zero self-hosting, OpenRouter is the fastest way to start.
Sources
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MIT licensed. No credit card, no fee on your API calls.
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