LiteLLM alternatives open source: Portkey and OpenRouter

Two documented options for teams leaving LiteLLM, as checked 2026-10-14: Portkey, whose gateway repository reports an MIT license, and OpenRouter, which exposes an OpenAI-compatible API at openrouter.ai whose license and pricing the cited sources do not state. Portkey's sources describe a gateway; OpenRouter's describe an API endpoint and SDKs.

Quick comparison

Why teams look beyond LiteLLM

The cited sources do not give reasons for leaving LiteLLM, so treat these as criteria to check rather than documented complaints.

• License clarity: the GitHub API does not report a recognized license for the LiteLLM repository, while it reports MIT for Portkey's gateway repository.
• Packaging: LiteLLM's docs describe a Python SDK, a separate litellm-core package and a self-hosted proxy with an admin UI. Check whether you need all of that.
• Hosting model: decide whether you want to run a gateway yourself or call a provider-hosted endpoint.

LiteLLM itself is described in its docs as an open-source library giving a unified interface to 100+ LLMs in the OpenAI format, with a self-hosted gateway offering virtual keys, cost tracking and an admin UI. See the LiteLLM hub for more.

How the options differ

Portkey

The Portkey gateway repository describes an AI gateway with integrated guardrails that routes to 1,600+ LLMs and 50+ guardrails through one API. Its topics include mcp-gateway and model-router.

Portkey's docs show a native SDK in Python and Node, plus a curl call to api.portkey.ai/v1/chat/completions. They also show the OpenAI SDK pointed at a Portkey gateway URL with Portkey headers.

For enterprises, the docs say managed hosting is available to deploy Portkey inside private clouds. They also say a feature that does not store request and response bodies can be enabled on request. The docs page is titled as Prisma AIRS AI Gateway, so check naming and packaging before you plan.

OpenRouter

OpenRouter's quickstart shows a chat completions endpoint at https://openrouter.ai/api/v1/chat/completions. Examples cover Python requests, fetch, curl, and the OpenAI SDK with a changed base URL.

The docs also list an @openrouter/sdk package, a Python openrouter client, an @openrouter/agent package for tool use, and an MCP URL.

Practical migration notes

Application code that uses LiteLLM's completion() interface will need to change. Both alternatives show chat-completions style calls, so the message format in the examples is similar to LiteLLM's OpenAI-format responses.

• API surface: both alternatives' docs show the OpenAI SDK working with a changed base URL. OpenRouter needs a bearer key, and Portkey needs a Portkey key plus provider headers.
• Model names: LiteLLM uses provider-prefixed names such as openai/.... OpenRouter's examples use names such as ~openai/.... Portkey's examples pass a provider separately. Map names before cutover.
• Self-hosting: the Portkey repository is public under MIT. Whether OpenRouter can be self-hosted is not stated in the cited sources.
• Proxy features: LiteLLM's virtual keys, cost tracking and admin UI have no documented one-to-one equivalent in the excerpts we read. Verify each one you rely on.

How we compared

We read the GitHub repository metadata for Portkey and LiteLLM, the Portkey introduction docs, the OpenRouter quickstart and the LiteLLM getting-started docs. All were checked on 2026-10-14. We did not run any gateway, measure latency or cost, or test migration of a real LiteLLM config.

Limitations

• Pricing, free tiers and rate limits are not stated in the cited sources for either option.
• OpenRouter's license and self-hosting options are not stated.
• No source here states Go support. LiteLLM's repo mentions a Rust core, but no Rust or Go alternative is documented in these sources.
• Provider coverage, streaming and function-calling parity with LiteLLM are not verified.
• A repository license does not imply that any hosted service is free.

Related: LiteLLM hub, Portkey hub, OpenRouter hub, Agent infra category and the broader guide Best LLM gateway: LiteLLM, Portkey, OpenRouter compared.