GPT-5 Nano vs GPT-OSS 20B

1. Extremely fast performance

• Fastest model in the GPT-5 family.
• Great for real-time workflows, rapid responses, and high-throughput systems.

2. Most cost-efficient GPT-5 model

• Lowest input and output token costs.
• Suitable for large-scale or budget-sensitive applications.

3. Ideal for lightweight, well-scoped tasks

• Excels at summarization, classification, text extraction, and simple logic tasks.
• Best used when tasks are narrow and well-defined.

4. Multimodal input

• Accepts text + image as input.
• Outputs text only.

5. Broad tool support

• Supports Web Search, File Search, Image Generation (as a tool), Code Interpreter, and MCP.
• (Does not support Computer Use.)

• Open-weight / Apache 2.0 licensed: you can use, modify, and deploy freely (commercially & academically) under permissive terms.
• Large model size (≈ 21B parameters) with Mixture-of-Experts (MoE) architecture: only ~3.6B parameters active per token, yielding efficient inference.
• Very long context window support: up to ~128 K tokens (or ~131 K tokens per some sources) enabling in-depth reasoning, long documents, or multi-turn context.
• Adjustable reasoning effort: you can trade latency vs quality by tuning “reasoning effort” levels.
• Efficient hardware requirements (for its class): designed to run on a single 16 GB-class GPU or optimized local deployments for lower latency applications.
• Strong for tasks such as reasoning, tool-use, structured output, chain-of-thought debugging: because the model is open and you can inspect its chain of thought.
• Flexibility: since weights are available, you can self-host, fine-tune, or deploy offline, giving more control than closed API models.