1. Advanced reasoning capability

• Designed for multi-step thinking across text, code, and visual inputs.
• Excels at math, science, logic puzzles, and complex analytical workflows.

2. Strong performance across domains

• Highly capable in technical writing, data analysis, and structured problem-solving.
• Useful for research, engineering tasks, and intricate instruction-following.

3. Visual reasoning support

• Accepts image inputs, enabling tasks such as diagram analysis, chart interpretation, and visual logic assessments.

4. High output capacity

• Up to 100,000 output tokens, supporting long-form content, technical breakdowns, and multi-part solutions.

5. Excellent instruction following

• Produces detailed, step-by-step responses for tasks requiring precision and clarity.
• Ideal for educational explanations, system design reasoning, and code walkthroughs.

6. Large 200K context window

• Handles long documents, multi-file reasoning, or extended conversations with minimal loss of context.

7. Broad API support

• Works with Chat Completions, Responses, Realtime, Assistants, Batch, Embeddings, Image Generation, and more.
• Supports streaming and function calling for advanced workflows.

8. Positioned as a legacy reasoning model

• Remains extremely capable but formally succeeded by GPT-5, which offers stronger reasoning and performance.

1. Maximum-compute o-series model

• Uses significantly more compute per query compared to o1.
• Produces deeper, more reliable reasoning chains.
• Best suited for high-stakes tasks that need correctness over speed.

2. Trained with reinforcement learning for deliberate thinking

• Explicit "think-before-answer" architecture.
• Excels at complex reasoning requiring multi-step analysis.

3. Very strong at math, science, coding, and technical proofs

• Handles long derivations, algorithm design, and difficult logic problems.
• Produces structured and explainable reasoning trails.

4. Great for multi-turn reasoning workflows

• Responses API optimized: can think over multiple internal turns before responding.
• Ideal for agentic reasoning pipelines.

5. Large context window

• 200,000-token context for large documents, multi-file review, and long reasoning traces.

6. Multimodal input (text + image)

• Can analyze images for mathematical diagrams, charts, handwritten content, UI layouts, etc.
• Output is text only.

7. Consistency, reliability, and depth

• Designed for situations where accuracy matters more than latency or cost.
• Strong error-checking and self-correction abilities.