GPT-5.2 Codex vs GPT-5 Nano

1. Optimized for Long-Horizon Coding Tasks

• OpenAI describes GPT-5.2 Codex as a highly intelligent coding model built for long-horizon, agentic coding work.
• Well suited to planning, refactoring, debugging, and multi-step implementation flows inside real codebases.

2. Adjustable Reasoning for Coding Work

• Supports configurable reasoning effort from low to xhigh depending on speed and quality needs.
• Accepts both text and image inputs while producing text output.

3. Large Context + Long Output

• 400 k token context window supports broad repository understanding and larger working sets.
• Allows up to 128 k output tokens for longer patches, code generation, and technical explanations.

4. Up-to-Date Model Snapshot

• Knowledge cut-off of Aug 31 2025 keeps it current with newer tools and frameworks.
• Supports streaming, function calling, and structured outputs for tool-driven coding workflows.

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.)