The deciding difference is operational: LiteLLM can run on infrastructure you control, Google Vertex AI cannot. If that constraint is real for you, it settles the choice before anything else is considered.
Claude and Gemini under GCP billing, IAM and regional controls.
Self-hosted proxy that speaks one API to 100+ providers, with keys and budgets.
Give every agent its own virtual key so you can attribute and cap spend per surface.
| Google Vertex AI | LiteLLM | |
|---|---|---|
| Licence | Proprietary | Open source |
| Pricing | usage based | open source |
| Self-hostable | No | Yes |
| Languages | TypeScript, Python | Python, TypeScript |
| Install | — | pip install 'litellm[proxy]' |
| Keys required | GOOGLE_CLOUD_PROJECT, GOOGLE_APPLICATION_CREDENTIALS | None |
The deciding difference is operational: LiteLLM can run on infrastructure you control, Google Vertex AI cannot. If that constraint is real for you, it settles the choice before anything else is considered. Google Vertex AI: Claude and Gemini under GCP billing, IAM and regional controls. LiteLLM: Self-hosted proxy that speaks one API to 100+ providers, with keys and budgets.
Google Vertex AI is a hosted service only. LiteLLM can run on your own infrastructure.
Google Vertex AI is proprietary (usage based). LiteLLM is open source (open source).
Every page here answers to Accept: text/markdown and returns the same content at roughly a tenth the tokens. No separate site, no toggle — same URL.
curl -s -H "Accept: text/markdown" https://newagent.build/compare/vertex-vs-litellm