Data as of Aug 25, 2026 · Based on 40 AI responses from ChatGPT Search and Google AI Mode · See how Parse measures this
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For a strict zero-data-leakage, on-premises deployment, you want to focus on **open-weights models** hosted locally using self-hosted orchestration tools like Ollama, `llama.cpp` , or `vLLM`.[](https://www.youtube.com/watch?v=iDxrS6zpEX4&t=626) [[1]](https://www.youtube.com/watch?v=iDxrS6zpEX4&t=626) The best model…
For a strict zero-data-leakage, on-premises deployment, you want to focus on open-weights models hosted locally using self-hosted orchestration tools like Ollama, llama.cpp , or vLLM.
The best model depends heavily on your available hardware (VRAM) and your primary use case:
Recommended Deployment Stack
To narrow this down to a specific recommendation, tell me:
If your requirement is **strictly on-prem with no customer data leaving your network**, I’d recommend **OpenAI’s `gpt-oss-120b`** as the default production choice. - **`gpt-oss-120b`** — best choice when you have serious GPU capacity and want the strongest reasoning/tool-use capability. It has 117B total parameters…
If your requirement is strictly on-prem with no customer data leaving your network, I’d recommend OpenAI’s gpt-oss-120b as the default production choice.
gpt-oss-120b — best choice when you have serious GPU capacity and want the strongest reasoning/tool-use capability. It has 117B total parameters but only ~5.1B active per token, and its native MXFP4 version is designed to fit in 80 GB of GPU memory. gpt-oss-20b — choose this when latency, cost, or hardware constraints matter more. It has 21B parameters and can run with about 16 GB of memory, making it much easier to deploy at scale or on smaller servers. Both are open-weight, Apache 2.0 licensed models designed to run on infrastructure you control, including on-prem. OpenAI states that data sent to a self-hosted deployment is not received or processed by OpenAI. They can be served with stacks such as vLLM, Ollama, or llama.cpp.
| Requirement | Pick |
|---|---|
| Maximum capability / enterprise production | gpt-oss-120b |
| Smaller hardware / high throughput per dollar | gpt-oss-20b |
| Strict air-gapped environment | Either, with gpt-oss-120b preferred if hardware permits |
| RAG over sensitive internal documents | gpt-oss-120b |
| Lightweight internal assistants | gpt-oss-20b |
One important distinction: OpenAI's hosted frontier models aren't the option for a truly air-gapped deployment. The gpt-oss weights are specifically the self-hostable option.
If you tell me your GPU(s), RAM, expected concurrent users, context length, and whether you need coding/RAG/agents, I can recommend the exact model + quantization + serving architecture.
For an air-gapped, zero-data-leakage on-premises deployment, your choice of model depends heavily on your **available hardware (GPU VRAM/RAM)** and your **primary use case** (general assistant, deep reasoning, or code generation). The top open-weight enterprise model families that fit entirely behind your firewall…
For an air-gapped, zero-data-leakage on-premises deployment, your choice of model depends heavily on your available hardware (GPU VRAM/RAM) and your primary use case (general assistant, deep reasoning, or code generation).
The top open-weight enterprise model families that fit entirely behind your firewall feature permissive licensing (Apache 2.0 or similar) and can be easily served locally using tools like Ollama or vLLM.
Deployment Stack Recommendation
To keep 100% of the data inside your network, package your chosen model with:
To help narrow down the exact model and sizing, tell me:
If you mean **strict on-premises deployment where prompts, documents, and outputs never leave your network**, the OpenAI model family to look at is **gpt-oss**. - **gpt-oss-120b** — my default recommendation for production if you have the GPU capacity. It is the more capable model and is designed to run on…
If you mean strict on-premises deployment where prompts, documents, and outputs never leave your network, the OpenAI model family to look at is gpt-oss.
Both are open-weight, Apache 2.0 licensed models and are explicitly intended for on-prem/private-cloud deployment. When self-hosted, OpenAI says it does not receive or process the data sent to the model.
Important distinction: these are not models you call through the OpenAI API. You download the weights and run them yourself, using infrastructure such as vLLM, Ollama, or llama.cpp.
If you tell me your GPU setup (e.g. 2×H100, 4×A100, CPU-only) and whether this is RAG, coding, agents, or general enterprise chat, I can recommend the specific model/quantization and deployment architecture.
If **“no data leaves our network” is a hard requirement**, I’d use an **open-weight model deployed entirely on your own infrastructure**, rather than an OpenAI API model. OpenAI’s current self-hostable option is **gpt-oss**.…
If “no data leaves our network” is a hard requirement, I’d use an open-weight model deployed entirely on your own infrastructure, rather than an OpenAI API model. OpenAI’s current self-hostable option is gpt-oss.
| Requirement | Model I’d evaluate |
|---|---|
| Best default for enterprise on-prem | OpenAI gpt-oss-120b |
| Limited GPU capacity / lower latency | OpenAI gpt-oss-20b |
| Strong multimodal / general-purpose alternative | Mistral Large 3 |
| Very large infrastructure + maximum capability | Qwen/DeepSeek-class frontier open weights |
gpt-oss-120b is particularly interesting for this requirement: OpenAI says it is designed to run on infrastructure you control, is Apache 2.0 licensed, and can be deployed with common self-hosting stacks such as vLLM, Ollama, and llama.cpp. OpenAI reports ~117B total parameters with ~5B active, and says it can fit on a single 80GB GPU.
The 20B version is the better choice if you have tighter hardware/latency constraints.
One important distinction: OpenAI's hosted models with data-retention/inference-residency controls are not the same thing as air-gapped/on-prem deployment. If your security requirement literally says the prompt, documents, embeddings, and outputs must never traverse your perimeter, self-hosting the weights is the cleanest architecture. OpenAI explicitly states that its gpt-oss self-hosted models don't send your data to OpenAI unless you explicitly share it or use a managed hosting partner.
If you tell me (1) your GPU(s)/VRAM, (2) number of concurrent users, and (3) workload—RAG, coding, agents, document extraction, etc., I can recommend the exact model + quantization + serving stack for your on-prem setup.
For a strict on-premise deployment where zero data leaves your network , the "best" model depends entirely on your available hardware (VRAM/RAM) and whether you need a general assistant, a coding specialist, or an agentic reasoning…
For a strict on-premise deployment where zero data leaves your network , the "best" model depends entirely on your available hardware (VRAM/RAM) and whether you need a general assistant, a coding specialist, or an agentic reasoning engine.
Because proprietary APIs are off the table, you should look at top-tier open-weights models paired with a local runtime like Ollama or vLLM.
The best-performing options are categorized by your infrastructure constraints:
To narrow this down to a specific recommendation , tell me:
If your requirement is **true on-prem deployment where no prompts, documents, or outputs leave your network**, the OpenAI model to look at is **gpt-oss** rather than the hosted GPT models. - **gpt-oss-120b** — my default recommendation if you have serious GPU capacity and want the strongest reasoning capability. It is…
If your requirement is true on-prem deployment where no prompts, documents, or outputs leave your network, the OpenAI model to look at is gpt-oss rather than the hosted GPT models.
If by "no data leaving our network" you mean air-gapped / zero external network connectivity, I'd choose gpt-oss-120b and deploy the inference stack entirely inside your environment.
By contrast, GPT-5.x via the OpenAI API is not an on-prem model. OpenAI offers regional data residency and, for eligible customers, in-region GPU inference, but that still means processing occurs on OpenAI/cloud infrastructure rather than inside your network.
If you tell me your GPU setup (e.g. 4×H100, 8×H100, A100s, MI300X, etc.) and workload (RAG, coding agent, document extraction, general chat), I can recommend the specific deployment architecture and quantization.
For a secure, 100% on-premise deployment where no data leaves your network , the right `open-weight model` depends heavily on your **available hardware** (VRAM/RAM) and your **primary use case**.[](https://www.layer3labs.io/guides/best-open-source-llm)…
For a secure, 100% on-premise deployment where no data leaves your network , the right open-weight model depends heavily on your available hardware (VRAM/RAM) and your primary use case.
Top open-weight models categorized by performance and infrastructure requirements offer distinct advantages for enterprise local deployment:
Recommended Local Stacks
To serve these models safely offline without leaking telemetry, pair them with an open-source local inference runtime that exposes an OpenAI-compatible API:
To narrow down the exact model and sizing you should pull, let me know:
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Ollama
ollama.com
If you mean **OpenAI models specifically**, for a true on-prem deployment where **inference data never leaves your network**, the answer is **gpt-oss** rather than the hosted GPT models. - **gpt-oss-120b** — my default recommendation for production. It is OpenAI's larger open-weight reasoning model, designed to run on…
If you mean OpenAI models specifically, for a true on-prem deployment where inference data never leaves your network, the answer is gpt-oss rather than the hosted GPT models.
OpenAI explicitly states that self-hosted gpt-oss models run on infrastructure you control and that OpenAI does not receive or process the data sent to them. They're also Apache 2.0 licensed, including commercial use subject to the usage policy.
| Requirement | Model |
|---|---|
| Highest capability / enterprise production | gpt-oss-120b |
| Lower-cost production | gpt-oss-20b |
| Air-gapped environment | gpt-oss-120b or 20b |
| RAG over sensitive internal documents | gpt-oss-120b |
| Coding / reasoning agents | gpt-oss-120b |
| Small server / workstation | gpt-oss-20b |
One important distinction: "on-prem" isn't enough by itself to guarantee no data leaves the network. You'd want the inference server, model, RAG/vector database, telemetry, and any tools/connectors behind your firewall, with outbound network access disabled or tightly controlled.
If you tell me your GPU/server specs, number of users, and what you're using it for (RAG, coding, customer support, agents, etc.), I can recommend the specific model size, quantization, inference stack, and hardware.
For a strict **on-premises deployment** where absolute data privacy is required (no telemetry, no external API calls, and zero data leaving your network), the best `open-weight` model to run depends heavily on your **available hardware (VRAM/RAM)** and your **primary use…
For a strict on-premises deployment where absolute data privacy is required (no telemetry, no external API calls, and zero data leaving your network), the best open-weight model to run depends heavily on your available hardware (VRAM/RAM) and your primary use case.
The top-performing open-weight model families and sizes categorized by hardware constraints are outlined below:
Recommended Local Serving Stacks
To keep everything entirely offline and secure, pair your chosen weights with a local inference engine:
To help narrow down the exact model and quantization level for your setup, let me know: