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.

1. Strong reasoning for its generation

• Next-gen version of GPT-4 designed to be cheaper and faster than the original.
• Good for analytical tasks, structured writing, coding guidance, and multi-step reasoning.

2. Image input support

• Accepts images and provides text-only outputs.
• Useful for OCR, visual Q&A, document extraction, UI analysis, and design interpretation.

3. Stable performance

• Predictable model behavior suitable for legacy systems still built on GPT-4.
• Works reliably for established pipelines and enterprise workloads.

4. Large 128K context window

• Handles long documents, multi-file inputs, or extended conversational sessions.
• Allows complex prompt chaining and large instruction sets.

5. Broad endpoint compatibility

• Works with Chat Completions, Responses API, Realtime API, Assistants, Batch, Fine-tuning, Embeddings, and more.
• Supports streaming and function calling.

6. Good choice for cost-controlled GPT-4-class workloads

• Although older, still useful for teams who want GPT-4-level reasoning without upgrading immediately.
• A midpoint between legacy GPT-4 and modern GPT-4o/5.1 models.

7. Text-only output simplifies downstream use

• Ensures deterministic outputs for applications that need reliable text generation.
• Good for RAG, data pipelines, automation tools, and enterprise systems.

8. Recommended migration path

• OpenAI now recommends using GPT-4o or GPT-5.1 for improved speed, cost, reasoning, and multimodal capability.
• GPT-4 Turbo remains available for backward compatibility and stability.