Azure OpenAI vs self-hosted private AI
Both can satisfy strict IT policies. The difference is whether your data leaves your tenancy for a vendor-managed model endpoint — or runs on infrastructure you own end-to-end.
Choose Azure OpenAI if
- You are already standardized on Microsoft Azure
- Your compliance model accepts Microsoft as a data processor with a BAA
- You want OpenAI models without operating GPU infrastructure
- You have internal staff to integrate, monitor, and govern the service
Choose self-hosted private AI if
- Policy requires inference within infrastructure you solely control
- You want to avoid per-token cloud inference costs at scale
- You need custom retrieval and workflows beyond a hosted API
- You do not want to become an infrastructure team — but want ownership
The architectural split
Azure OpenAI Service hosts OpenAI models in Microsoft's cloud. Your applications call Azure endpoints; Microsoft operates the model serving layer. Self-hosted private AI runs open-weight models on compute you control — a private server, dedicated cloud tenancy, or on-prem hardware — with no vendor inference path per request.
| Factor | Azure OpenAI | Self-hosted (IlluminAI) |
|---|---|---|
| Control plane | Microsoft Azure | Your accounts and keys |
| Model lineage | OpenAI models via Azure | Open-weight models you select |
| Compliance framing | BAA / DPA with Microsoft | No external inference processor |
| Customization | RAG via your apps + Azure APIs | Custom workflows, agents, data layer built for you |
| Ops burden | Your IT + Azure monitoring | Managed by IlluminAI under your ownership |
| Cost shape | Consumption-based API pricing | Fixed-scope build + infra you pay directly |
When teams switch or add private deployment
Common triggers: a client or regulator asks where prompts go; inference spend grows faster than headcount; or counsel wants a demonstrable air gap for certain matter types. Some firms run Azure OpenAI for low-sensitivity work and private deployment for confidential workflows — that hybrid is valid when scoped explicitly.
Last verified: 2026-09-18 · Sources: Microsoft Azure OpenAI Service documentation (deployment model); IlluminAI deployment pattern on client-owned infrastructure.