1. Extremely low-cost text model

• One of the cheapest legacy models available.
• Suitable for very high-volume workloads with simple requirements.

2. Good for lightweight NLP tasks

• Classification, summarization, rewriting, paraphrasing, intent detection.
• Works for simple logic tasks and short reasoning sequences.

3. Works well for basic chatbots

• Optimized for Chat Completions API, originally powering early ChatGPT use cases.
• Good for rule-based or templated conversation flows.

4. Stable and predictable outputs

• Legacy behavior makes it suitable for systems built years ago that rely on its quirks.
• Good for backward compatibility or long-term enterprise pipelines.

5. Supports fine-tuning

• Useful for teams maintaining older fine-tuned GPT-3.5 models.
• Allows domain-specific compression of older datasets.

6. Limited capabilities compared to newer models

• No vision, no audio, no streaming, and no function calling.
• Much weaker reasoning and correctness vs GPT-4o mini or GPT-5.1.

7. Small context window (16K)

• Limited for multi-document tasks or long conversations.
• Best used for short, simple prompts or structured tasks.

8. Recommended migration path

• OpenAI explicitly recommends using GPT-4o mini instead.
• 4o mini is cheaper, smarter, faster, multimodal, and far more capable.

1. Intelligence & Reasoning

• Outperforms previous Claude models and competitor LLMs across major benchmarks.
• Excels in graduate-level reasoning (GPQA), knowledge tasks (MMLU), and coding (HumanEval).
• Handles nuance, humor, and complex instructions with human-like clarity.

2. Speed & Efficiency

• Runs 2x faster than Claude 3 Opus, making it ideal for real-time and high-volume workflows.
• Cost-effective pricing: $3/M input tokens and $15/M output tokens.
• Supports a 200K token context window, enabling rich, long-form reasoning.

3. Coding Capabilities

• Solves significantly more coding and bug-fix tasks (64% vs Opus's 38% in internal evaluations).
• Can autonomously write, edit, and execute code when tool use is enabled.
• Strong at translating and modernizing legacy codebases.

4. Vision Strength

• Best vision model in the Claude family, surpassing Opus on vision benchmarks.
• Excellent at interpreting charts, graphs, and imperfect images.
• Reliable text extraction from low-quality visuals for retail, logistics, finance, etc.

5. Agentic Workflows

• Highly capable for multi-step task orchestration.
• Performs well as the engine for agents requiring reasoning, planning, and tool-calling abilities.

6. Content Quality

• Produces natural, relatable writing with improved tone, style, and context awareness.
• Strong at long-form content creation and editing.

7. Safety & Reliability

• Rated ASL-2, meeting Anthropic's safety standards.
• Undergoes extensive red-teaming and external evaluation (UK AISI & US AISI).
• Not trained on user data without explicit permission.